diff --git a/ballerina-tests/69_package_with_multiple_imports_pb.bal b/ballerina-tests/69_package_with_multiple_imports_pb.bal
index a8a416a77..6a416c4ea 100644
--- a/ballerina-tests/69_package_with_multiple_imports_pb.bal
+++ b/ballerina-tests/69_package_with_multiple_imports_pb.bal
@@ -105,8 +105,8 @@ public isolated client class packagingServiceClient {
     }
 }
 
-public client class Hello3StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Hello3StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -173,8 +173,8 @@ public class ResMessage2Stream {
     }
 }
 
-public client class Hello4StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Hello4StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -217,8 +217,8 @@ public client class Hello4StreamingClient {
     }
 }
 
-public client class Hello5StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Hello5StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -261,8 +261,8 @@ public client class Hello5StreamingClient {
     }
 }
 
-public client class PackagingServiceRootMessageCaller {
-    private grpc:Caller caller;
+public isolated client class PackagingServiceRootMessageCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -293,8 +293,8 @@ public client class PackagingServiceRootMessageCaller {
     }
 }
 
-public client class PackagingServiceResMessage2Caller {
-    private grpc:Caller caller;
+public isolated client class PackagingServiceResMessage2Caller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/70_package_with_nested_modules_pb.bal b/ballerina-tests/70_package_with_nested_modules_pb.bal
index b1f906c26..3359decb1 100644
--- a/ballerina-tests/70_package_with_nested_modules_pb.bal
+++ b/ballerina-tests/70_package_with_nested_modules_pb.bal
@@ -99,8 +99,8 @@ public isolated client class helloWorld70Client {
     }
 }
 
-public client class HelloWorld70ClientStreamStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class HelloWorld70ClientStreamStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -167,8 +167,8 @@ public class ResMessageStream {
     }
 }
 
-public client class HelloWorld70BidiStreamStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class HelloWorld70BidiStreamStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -211,8 +211,8 @@ public client class HelloWorld70BidiStreamStreamingClient {
     }
 }
 
-public client class HelloWorld70ResMessageCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld70ResMessageCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/71_package_with_service_in_submodule_pb.bal b/ballerina-tests/71_package_with_service_in_submodule_pb.bal
index 708787cdc..9cc452ad9 100644
--- a/ballerina-tests/71_package_with_service_in_submodule_pb.bal
+++ b/ballerina-tests/71_package_with_service_in_submodule_pb.bal
@@ -98,8 +98,8 @@ public isolated client class helloWorld71Client {
     }
 }
 
-public client class HelloWorld71ClientStreamStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class HelloWorld71ClientStreamStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -142,8 +142,8 @@ public client class HelloWorld71ClientStreamStreamingClient {
     }
 }
 
-public client class HelloWorld71BidiStreamStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class HelloWorld71BidiStreamStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -186,8 +186,8 @@ public client class HelloWorld71BidiStreamStreamingClient {
     }
 }
 
-public client class HelloWorld71ResMessageCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld71ResMessageCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/modules/messageWithService/71_message_pb.bal b/ballerina-tests/modules/messageWithService/71_message_pb.bal
index f40c36054..b147519a7 100644
--- a/ballerina-tests/modules/messageWithService/71_message_pb.bal
+++ b/ballerina-tests/modules/messageWithService/71_message_pb.bal
@@ -98,8 +98,8 @@ public isolated client class helloBallerina71Client {
     }
 }
 
-public client class HelloStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class HelloStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -166,8 +166,8 @@ public class ResMessageStream {
     }
 }
 
-public client class ByeStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ByeStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -210,8 +210,8 @@ public client class ByeStreamingClient {
     }
 }
 
-public client class HelloBallerina71ResMessageCaller {
-    private grpc:Caller caller;
+public isolated client class HelloBallerina71ResMessageCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/01_advanced_type_service_pb.bal b/ballerina-tests/tests/01_advanced_type_service_pb.bal
index cd7eb7649..8741c2ccc 100644
--- a/ballerina-tests/tests/01_advanced_type_service_pb.bal
+++ b/ballerina-tests/tests/01_advanced_type_service_pb.bal
@@ -169,8 +169,8 @@ public isolated client class HelloWorldClient {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -201,8 +201,8 @@ public client class HelloWorldStringCaller {
     }
 }
 
-public client class HelloWorldNilCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldNilCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -225,8 +225,8 @@ public client class HelloWorldNilCaller {
     }
 }
 
-public client class HelloWorldPersonCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldPersonCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -257,8 +257,8 @@ public client class HelloWorldPersonCaller {
     }
 }
 
-public client class HelloWorldStockNamesCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStockNamesCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -289,8 +289,8 @@ public client class HelloWorldStockNamesCaller {
     }
 }
 
-public client class HelloWorldStockQuotesCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStockQuotesCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -321,8 +321,8 @@ public client class HelloWorldStockQuotesCaller {
     }
 }
 
-public client class HelloWorldStockQuoteCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStockQuoteCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/02_array_field_type_service_pb.bal b/ballerina-tests/tests/02_array_field_type_service_pb.bal
index b62cb649f..ee7f1f022 100644
--- a/ballerina-tests/tests/02_array_field_type_service_pb.bal
+++ b/ballerina-tests/tests/02_array_field_type_service_pb.bal
@@ -252,8 +252,8 @@ public isolated client class HelloWorld3Client {
     }
 }
 
-public client class HelloWorld3FloatCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld3FloatCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -284,8 +284,8 @@ public client class HelloWorld3FloatCaller {
     }
 }
 
-public client class HelloWorld3IntCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld3IntCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -316,8 +316,8 @@ public client class HelloWorld3IntCaller {
     }
 }
 
-public client class HelloWorld3TestFloatCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld3TestFloatCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -348,8 +348,8 @@ public client class HelloWorld3TestFloatCaller {
     }
 }
 
-public client class HelloWorld3TestBooleanCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld3TestBooleanCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -380,8 +380,8 @@ public client class HelloWorld3TestBooleanCaller {
     }
 }
 
-public client class HelloWorld3BooleanCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld3BooleanCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -412,8 +412,8 @@ public client class HelloWorld3BooleanCaller {
     }
 }
 
-public client class HelloWorld3TestIntCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld3TestIntCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -444,8 +444,8 @@ public client class HelloWorld3TestIntCaller {
     }
 }
 
-public client class HelloWorld3StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld3StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -476,8 +476,8 @@ public client class HelloWorld3StringCaller {
     }
 }
 
-public client class HelloWorld3TestStructCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld3TestStructCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -508,8 +508,8 @@ public client class HelloWorld3TestStructCaller {
     }
 }
 
-public client class HelloWorld3TestStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld3TestStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/03_bidirectional_streaming_service_pb.bal b/ballerina-tests/tests/03_bidirectional_streaming_service_pb.bal
index a1249bac8..de40aec78 100644
--- a/ballerina-tests/tests/03_bidirectional_streaming_service_pb.bal
+++ b/ballerina-tests/tests/03_bidirectional_streaming_service_pb.bal
@@ -33,8 +33,8 @@ public isolated client class ChatClient {
     }
 }
 
-public client class ChatStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ChatStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -77,8 +77,8 @@ public client class ChatStreamingClient {
     }
 }
 
-public client class ChatStringCaller {
-    private grpc:Caller caller;
+public isolated client class ChatStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/04_client_streaming_service_pb.bal b/ballerina-tests/tests/04_client_streaming_service_pb.bal
index 7bfd796f1..704f285f9 100644
--- a/ballerina-tests/tests/04_client_streaming_service_pb.bal
+++ b/ballerina-tests/tests/04_client_streaming_service_pb.bal
@@ -33,8 +33,8 @@ public isolated client class HelloWorld7Client {
     }
 }
 
-public client class LotsOfGreetingsStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class LotsOfGreetingsStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -77,8 +77,8 @@ public client class LotsOfGreetingsStreamingClient {
     }
 }
 
-public client class HelloWorld7StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld7StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/05_invalid_resource_service_pb.bal b/ballerina-tests/tests/05_invalid_resource_service_pb.bal
index a1992909e..66a5e7df9 100644
--- a/ballerina-tests/tests/05_invalid_resource_service_pb.bal
+++ b/ballerina-tests/tests/05_invalid_resource_service_pb.bal
@@ -86,8 +86,8 @@ public isolated client class HelloWorld98Client {
     }
 }
 
-public client class HelloWorld98IntCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld98IntCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -118,8 +118,8 @@ public client class HelloWorld98IntCaller {
     }
 }
 
-public client class HelloWorld98StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld98StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/06_server_streaming_service_pb.bal b/ballerina-tests/tests/06_server_streaming_service_pb.bal
index 27ec886d2..929122c09 100644
--- a/ballerina-tests/tests/06_server_streaming_service_pb.bal
+++ b/ballerina-tests/tests/06_server_streaming_service_pb.bal
@@ -59,8 +59,8 @@ public isolated client class HelloWorld45Client {
     }
 }
 
-public client class HelloWorld45StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld45StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/07_unary_server_pb.bal b/ballerina-tests/tests/07_unary_server_pb.bal
index c4dbfa82e..9b03cb627 100644
--- a/ballerina-tests/tests/07_unary_server_pb.bal
+++ b/ballerina-tests/tests/07_unary_server_pb.bal
@@ -242,8 +242,8 @@ public isolated client class HelloWorld100Client {
     }
 }
 
-public client class HelloWorld100BooleanCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld100BooleanCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -274,8 +274,8 @@ public client class HelloWorld100BooleanCaller {
     }
 }
 
-public client class HelloWorld100StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld100StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -306,8 +306,8 @@ public client class HelloWorld100StringCaller {
     }
 }
 
-public client class HelloWorld100IntCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld100IntCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -338,8 +338,8 @@ public client class HelloWorld100IntCaller {
     }
 }
 
-public client class HelloWorld100NilCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld100NilCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -362,8 +362,8 @@ public client class HelloWorld100NilCaller {
     }
 }
 
-public client class HelloWorld100FloatCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld100FloatCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -394,8 +394,8 @@ public client class HelloWorld100FloatCaller {
     }
 }
 
-public client class HelloWorld100ResponseCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld100ResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/08_unary_service_with_headers_pb.bal b/ballerina-tests/tests/08_unary_service_with_headers_pb.bal
index 4ec233c10..de979ed9f 100644
--- a/ballerina-tests/tests/08_unary_service_with_headers_pb.bal
+++ b/ballerina-tests/tests/08_unary_service_with_headers_pb.bal
@@ -58,8 +58,8 @@ public isolated client class HelloWorld101Client {
     }
 }
 
-public client class HelloWorld101StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld101StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/09_grpc_secured_unary_service_pb.bal b/ballerina-tests/tests/09_grpc_secured_unary_service_pb.bal
index 2561451e3..6d28d8860 100644
--- a/ballerina-tests/tests/09_grpc_secured_unary_service_pb.bal
+++ b/ballerina-tests/tests/09_grpc_secured_unary_service_pb.bal
@@ -58,8 +58,8 @@ public isolated client class HelloWorld85Client {
     }
 }
 
-public client class HelloWorld85StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld85StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/10_grpc_ssl_server_pb.bal b/ballerina-tests/tests/10_grpc_ssl_server_pb.bal
index f573a7896..0beef66cb 100644
--- a/ballerina-tests/tests/10_grpc_ssl_server_pb.bal
+++ b/ballerina-tests/tests/10_grpc_ssl_server_pb.bal
@@ -58,8 +58,8 @@ public isolated client class GrpcMutualSslServiceClient {
     }
 }
 
-public client class GrpcMutualSslServiceStringCaller {
-    private grpc:Caller caller;
+public isolated client class GrpcMutualSslServiceStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/11_grpc_byte_service_pb.bal b/ballerina-tests/tests/11_grpc_byte_service_pb.bal
index ff3b85507..4b90602b4 100644
--- a/ballerina-tests/tests/11_grpc_byte_service_pb.bal
+++ b/ballerina-tests/tests/11_grpc_byte_service_pb.bal
@@ -58,8 +58,8 @@ public isolated client class ByteServiceClient {
     }
 }
 
-public client class ByteServiceByteCaller {
-    private grpc:Caller caller;
+public isolated client class ByteServiceByteCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/12_grpc_enum_test_service_pb.bal b/ballerina-tests/tests/12_grpc_enum_test_service_pb.bal
index efa925e97..59b72f75d 100644
--- a/ballerina-tests/tests/12_grpc_enum_test_service_pb.bal
+++ b/ballerina-tests/tests/12_grpc_enum_test_service_pb.bal
@@ -59,8 +59,8 @@ public isolated client class TestEnumServiceClient {
     }
 }
 
-public client class TestEnumServiceStringCaller {
-    private grpc:Caller caller;
+public isolated client class TestEnumServiceStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/13_grpc_service_with_error_return_pb.bal b/ballerina-tests/tests/13_grpc_service_with_error_return_pb.bal
index 36a7b04fd..2735cfbf8 100644
--- a/ballerina-tests/tests/13_grpc_service_with_error_return_pb.bal
+++ b/ballerina-tests/tests/13_grpc_service_with_error_return_pb.bal
@@ -58,8 +58,8 @@ public isolated client class HelloWorld13Client {
     }
 }
 
-public client class HelloWorld13StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld13StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/14_grpc_client_socket_timeout_pb.bal b/ballerina-tests/tests/14_grpc_client_socket_timeout_pb.bal
index ba0edbd8a..52c4efd4d 100644
--- a/ballerina-tests/tests/14_grpc_client_socket_timeout_pb.bal
+++ b/ballerina-tests/tests/14_grpc_client_socket_timeout_pb.bal
@@ -58,8 +58,8 @@ public isolated client class HelloWorld14Client {
     }
 }
 
-public client class HelloWorld14StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld14StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/15_grpc_oneof_field_service_pb.bal b/ballerina-tests/tests/15_grpc_oneof_field_service_pb.bal
index bdaec7094..9301ea3eb 100644
--- a/ballerina-tests/tests/15_grpc_oneof_field_service_pb.bal
+++ b/ballerina-tests/tests/15_grpc_oneof_field_service_pb.bal
@@ -86,8 +86,8 @@ public isolated client class OneofFieldServiceClient {
     }
 }
 
-public client class OneofFieldServiceZZZCaller {
-    private grpc:Caller caller;
+public isolated client class OneofFieldServiceZZZCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -118,8 +118,8 @@ public client class OneofFieldServiceZZZCaller {
     }
 }
 
-public client class OneofFieldServiceResponse1Caller {
-    private grpc:Caller caller;
+public isolated client class OneofFieldServiceResponse1Caller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/16_unavailable_service_client_pb.bal b/ballerina-tests/tests/16_unavailable_service_client_pb.bal
index 852d68719..6f84eb1b9 100644
--- a/ballerina-tests/tests/16_unavailable_service_client_pb.bal
+++ b/ballerina-tests/tests/16_unavailable_service_client_pb.bal
@@ -58,8 +58,8 @@ public isolated client class HelloWorld16Client {
     }
 }
 
-public client class HelloWorld16StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld16StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/18_grpc_optional_field_service_pb.bal b/ballerina-tests/tests/18_grpc_optional_field_service_pb.bal
index f6a73ad62..c470b830c 100644
--- a/ballerina-tests/tests/18_grpc_optional_field_service_pb.bal
+++ b/ballerina-tests/tests/18_grpc_optional_field_service_pb.bal
@@ -58,8 +58,8 @@ public isolated client class CheckoutServiceClient {
     }
 }
 
-public client class CheckoutServicePlaceOrderResponseCaller {
-    private grpc:Caller caller;
+public isolated client class CheckoutServicePlaceOrderResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/19_grpc_map_service_pb.bal b/ballerina-tests/tests/19_grpc_map_service_pb.bal
index 67e2ec1ae..efdbce51b 100644
--- a/ballerina-tests/tests/19_grpc_map_service_pb.bal
+++ b/ballerina-tests/tests/19_grpc_map_service_pb.bal
@@ -111,8 +111,8 @@ public isolated client class NegotiatorClient {
     }
 }
 
-public client class NegotiatorNilCaller {
-    private grpc:Caller caller;
+public isolated client class NegotiatorNilCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -135,8 +135,8 @@ public client class NegotiatorNilCaller {
     }
 }
 
-public client class NegotiatorHandshakeResponseCaller {
-    private grpc:Caller caller;
+public isolated client class NegotiatorHandshakeResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/20_unary_client_for_anonymous_service_pb.bal b/ballerina-tests/tests/20_unary_client_for_anonymous_service_pb.bal
index 53beea645..a92ae3b7a 100644
--- a/ballerina-tests/tests/20_unary_client_for_anonymous_service_pb.bal
+++ b/ballerina-tests/tests/20_unary_client_for_anonymous_service_pb.bal
@@ -244,8 +244,8 @@ public isolated client class AnonService4Client {
     }
 }
 
-public client class Hello2StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Hello2StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -288,8 +288,8 @@ public client class Hello2StreamingClient {
     }
 }
 
-//public client class Hello2StreamingClient {
-//    private grpc:StreamingClient sClient;
+//public isolated client class Hello2StreamingClient {
+//    private final grpc:StreamingClient sClient;
 //
 //    isolated function init(grpc:StreamingClient sClient) {
 //        self.sClient = sClient;
@@ -332,8 +332,8 @@ public client class Hello2StreamingClient {
 //    }
 //}
 
-public client class AnonService1StringCaller {
-    private grpc:Caller caller;
+public isolated client class AnonService1StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -364,8 +364,8 @@ public client class AnonService1StringCaller {
     }
 }
 
-public client class AnonService2StringCaller {
-    private grpc:Caller caller;
+public isolated client class AnonService2StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -396,8 +396,8 @@ public client class AnonService2StringCaller {
     }
 }
 
-public client class AnonService3StringCaller {
-    private grpc:Caller caller;
+public isolated client class AnonService3StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -428,8 +428,8 @@ public client class AnonService3StringCaller {
     }
 }
 
-public client class AnonService4StringCaller {
-    private grpc:Caller caller;
+public isolated client class AnonService4StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/21_grpc_gzip_encoding_service_pb.bal b/ballerina-tests/tests/21_grpc_gzip_encoding_service_pb.bal
index 50a174de7..db6d8ff80 100644
--- a/ballerina-tests/tests/21_grpc_gzip_encoding_service_pb.bal
+++ b/ballerina-tests/tests/21_grpc_gzip_encoding_service_pb.bal
@@ -87,8 +87,8 @@ public isolated client class OrderManagementClient {
     }
 }
 
-public client class OrderManagementOrderCaller {
-    private grpc:Caller caller;
+public isolated client class OrderManagementOrderCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -119,8 +119,8 @@ public client class OrderManagementOrderCaller {
     }
 }
 
-public client class OrderManagementStringCaller {
-    private grpc:Caller caller;
+public isolated client class OrderManagementStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/22_retry_service_pb.bal b/ballerina-tests/tests/22_retry_service_pb.bal
index a54ad1940..a5f684eb8 100644
--- a/ballerina-tests/tests/22_retry_service_pb.bal
+++ b/ballerina-tests/tests/22_retry_service_pb.bal
@@ -58,8 +58,8 @@ public isolated client class RetryServiceClient {
     }
 }
 
-public client class RetryServiceStringCaller {
-    private grpc:Caller caller;
+public isolated client class RetryServiceStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/23_server_streaming_with_record_service_pb.bal b/ballerina-tests/tests/23_server_streaming_with_record_service_pb.bal
index 472dcd3ef..b2fd4e8a9 100644
--- a/ballerina-tests/tests/23_server_streaming_with_record_service_pb.bal
+++ b/ballerina-tests/tests/23_server_streaming_with_record_service_pb.bal
@@ -84,8 +84,8 @@ public class HelloResponseStream {
     }
 }
 
-public client class HelloWorldServerStreamingHelloResponseCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldServerStreamingHelloResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/24_return_data_unary_pb.bal b/ballerina-tests/tests/24_return_data_unary_pb.bal
index 8516ec8b7..62ed702f4 100644
--- a/ballerina-tests/tests/24_return_data_unary_pb.bal
+++ b/ballerina-tests/tests/24_return_data_unary_pb.bal
@@ -281,8 +281,8 @@ public class SampleMsg24Stream {
     }
 }
 
-public client class HelloWorld24BooleanCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld24BooleanCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -313,8 +313,8 @@ public client class HelloWorld24BooleanCaller {
     }
 }
 
-public client class HelloWorld24ByteCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld24ByteCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -345,8 +345,8 @@ public client class HelloWorld24ByteCaller {
     }
 }
 
-public client class HelloWorld24StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld24StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -377,8 +377,8 @@ public client class HelloWorld24StringCaller {
     }
 }
 
-public client class HelloWorld24SampleMsg24Caller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld24SampleMsg24Caller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -409,8 +409,8 @@ public client class HelloWorld24SampleMsg24Caller {
     }
 }
 
-public client class HelloWorld24IntCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld24IntCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -441,8 +441,8 @@ public client class HelloWorld24IntCaller {
     }
 }
 
-public client class HelloWorld24FloatCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld24FloatCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/25_return_data_streaming_pb.bal b/ballerina-tests/tests/25_return_data_streaming_pb.bal
index 8ae6ed70d..0b5616ebe 100644
--- a/ballerina-tests/tests/25_return_data_streaming_pb.bal
+++ b/ballerina-tests/tests/25_return_data_streaming_pb.bal
@@ -61,8 +61,8 @@ public isolated client class HelloWorld25Client {
     }
 }
 
-public client class HelloWorld25StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld25StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/26_return_data_client_streaming_pb.bal b/ballerina-tests/tests/26_return_data_client_streaming_pb.bal
index 18cc6c7fd..d88dad3b0 100644
--- a/ballerina-tests/tests/26_return_data_client_streaming_pb.bal
+++ b/ballerina-tests/tests/26_return_data_client_streaming_pb.bal
@@ -35,8 +35,8 @@ public isolated client class HelloWorld26Client {
     }
 }
 
-//public client class LotsOfGreetingsStreamingClient {
-//    private grpc:StreamingClient sClient;
+//public isolated client class LotsOfGreetingsStreamingClient {
+//    private final grpc:StreamingClient sClient;
 //
 //    isolated function init(grpc:StreamingClient sClient) {
 //        self.sClient = sClient;
@@ -79,8 +79,8 @@ public isolated client class HelloWorld26Client {
 //    }
 //}
 
-public client class HelloWorld26StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld26StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/27_bidirectional_streaming_service_pb.bal b/ballerina-tests/tests/27_bidirectional_streaming_service_pb.bal
index 5b036bd72..ec62e8820 100644
--- a/ballerina-tests/tests/27_bidirectional_streaming_service_pb.bal
+++ b/ballerina-tests/tests/27_bidirectional_streaming_service_pb.bal
@@ -36,8 +36,8 @@ public isolated client class ChatFromReturnClient {
     }
 }
 
-public client class Chat27StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Chat27StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -80,8 +80,8 @@ public client class Chat27StreamingClient {
     }
 }
 
-public client class ChatFromReturnStringCaller {
-    private grpc:Caller caller;
+public isolated client class ChatFromReturnStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/28_unary_basic_auth_pb.bal b/ballerina-tests/tests/28_unary_basic_auth_pb.bal
index ef284b9b0..bcd743f4f 100644
--- a/ballerina-tests/tests/28_unary_basic_auth_pb.bal
+++ b/ballerina-tests/tests/28_unary_basic_auth_pb.bal
@@ -58,8 +58,8 @@ public isolated client class HelloWorld28Client {
     }
 }
 
-public client class HelloWorld28StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld28StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/29_unary_jwt_pb.bal b/ballerina-tests/tests/29_unary_jwt_pb.bal
index a8cf47dac..516be837c 100644
--- a/ballerina-tests/tests/29_unary_jwt_pb.bal
+++ b/ballerina-tests/tests/29_unary_jwt_pb.bal
@@ -86,8 +86,8 @@ public isolated client class HelloWorld29Client {
     }
 }
 
-public client class HelloWorld29StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld29StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/30_unary_oauth2_pb.bal b/ballerina-tests/tests/30_unary_oauth2_pb.bal
index 26d672bb4..dd28c8f60 100644
--- a/ballerina-tests/tests/30_unary_oauth2_pb.bal
+++ b/ballerina-tests/tests/30_unary_oauth2_pb.bal
@@ -114,8 +114,8 @@ public isolated client class HelloWorld30Client {
     }
 }
 
-public client class HelloWorld30StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld30StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/31_return_unary_pb.bal b/ballerina-tests/tests/31_return_unary_pb.bal
index ed6e6a293..de0da0f8a 100644
--- a/ballerina-tests/tests/31_return_unary_pb.bal
+++ b/ballerina-tests/tests/31_return_unary_pb.bal
@@ -58,8 +58,8 @@ public isolated client class HelloWorld31Client {
     }
 }
 
-public client class HelloWorld31SampleMsg31Caller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld31SampleMsg31Caller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/32_return_record_server_streaming_pb.bal b/ballerina-tests/tests/32_return_record_server_streaming_pb.bal
index 30e0337e7..155d6e71f 100644
--- a/ballerina-tests/tests/32_return_record_server_streaming_pb.bal
+++ b/ballerina-tests/tests/32_return_record_server_streaming_pb.bal
@@ -84,8 +84,8 @@ public class SampleMsg32Stream {
     }
 }
 
-public client class HelloWorld32SampleMsg32Caller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld32SampleMsg32Caller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/33_return_record_client_streaming_pb.bal b/ballerina-tests/tests/33_return_record_client_streaming_pb.bal
index 3d0bef01c..7f215fb46 100644
--- a/ballerina-tests/tests/33_return_record_client_streaming_pb.bal
+++ b/ballerina-tests/tests/33_return_record_client_streaming_pb.bal
@@ -35,8 +35,8 @@ public isolated client class HelloWorld33Client {
     }
 }
 
-public client class SayHelloStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class SayHelloStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -79,8 +79,8 @@ public client class SayHelloStreamingClient {
     }
 }
 
-public client class HelloWorld33SampleMsg33Caller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld33SampleMsg33Caller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/34_return_record_bidi_streaming_pb.bal b/ballerina-tests/tests/34_return_record_bidi_streaming_pb.bal
index 006964622..f636a5dd7 100644
--- a/ballerina-tests/tests/34_return_record_bidi_streaming_pb.bal
+++ b/ballerina-tests/tests/34_return_record_bidi_streaming_pb.bal
@@ -35,8 +35,8 @@ public isolated client class HelloWorld34Client {
     }
 }
 
-public client class SayHello34StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class SayHello34StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -79,8 +79,8 @@ public client class SayHello34StreamingClient {
     }
 }
 
-public client class HelloWorld34SampleMsg34Caller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld34SampleMsg34Caller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/35_unary_service_with_deadline_pb.bal b/ballerina-tests/tests/35_unary_service_with_deadline_pb.bal
index 5723bb620..83d703e90 100644
--- a/ballerina-tests/tests/35_unary_service_with_deadline_pb.bal
+++ b/ballerina-tests/tests/35_unary_service_with_deadline_pb.bal
@@ -86,8 +86,8 @@ public isolated client class HelloWorld35Client {
     }
 }
 
-public client class HelloWorld35StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld35StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/36_unary_service_with_deadline_propagation_pb.bal b/ballerina-tests/tests/36_unary_service_with_deadline_propagation_pb.bal
index 07225bce2..6ab112f8a 100644
--- a/ballerina-tests/tests/36_unary_service_with_deadline_propagation_pb.bal
+++ b/ballerina-tests/tests/36_unary_service_with_deadline_propagation_pb.bal
@@ -97,8 +97,8 @@ public isolated client class HelloWorld36S2Client {
     }
 }
 
-public client class HelloWorld36S1StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld36S1StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -129,8 +129,8 @@ public client class HelloWorld36S1StringCaller {
     }
 }
 
-public client class HelloWorld36S2StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld36S2StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/37_streaming_with_deadline_pb.bal b/ballerina-tests/tests/37_streaming_with_deadline_pb.bal
index e524fd255..b0c2c5439 100644
--- a/ballerina-tests/tests/37_streaming_with_deadline_pb.bal
+++ b/ballerina-tests/tests/37_streaming_with_deadline_pb.bal
@@ -35,8 +35,8 @@ public isolated client class HelloWorld37Client {
     }
 }
 
-public client class CallWithDeadlineStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class CallWithDeadlineStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -79,8 +79,8 @@ public client class CallWithDeadlineStreamingClient {
     }
 }
 
-public client class HelloWorld37StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld37StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/38_bidi_streaming_with_caller_pb.bal b/ballerina-tests/tests/38_bidi_streaming_with_caller_pb.bal
index daff9bf8e..a0b26122d 100644
--- a/ballerina-tests/tests/38_bidi_streaming_with_caller_pb.bal
+++ b/ballerina-tests/tests/38_bidi_streaming_with_caller_pb.bal
@@ -36,8 +36,8 @@ public isolated client class Chat38Client {
     }
 }
 
-public client class Chat38StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Chat38StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -80,8 +80,8 @@ public client class Chat38StreamingClient {
     }
 }
 
-public client class Chat38StringCaller {
-    private grpc:Caller caller;
+public isolated client class Chat38StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/39_unary_bearer_auth_pb.bal b/ballerina-tests/tests/39_unary_bearer_auth_pb.bal
index 2c3cbe7f9..e692b7ba2 100644
--- a/ballerina-tests/tests/39_unary_bearer_auth_pb.bal
+++ b/ballerina-tests/tests/39_unary_bearer_auth_pb.bal
@@ -58,8 +58,8 @@ public isolated client class HelloWorld39Client {
     }
 }
 
-public client class HelloWorld39StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld39StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/40_bidirectional_streaming_negative_test_pb.bal b/ballerina-tests/tests/40_bidirectional_streaming_negative_test_pb.bal
index 0b90e6b83..5863a5ee8 100644
--- a/ballerina-tests/tests/40_bidirectional_streaming_negative_test_pb.bal
+++ b/ballerina-tests/tests/40_bidirectional_streaming_negative_test_pb.bal
@@ -36,8 +36,8 @@ public isolated client class ChatWithCallerClient {
     }
 }
 
-public client class CallStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class CallStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -80,8 +80,8 @@ public client class CallStreamingClient {
     }
 }
 
-public client class ChatWithCallerStringCaller {
-    private grpc:Caller caller;
+public isolated client class ChatWithCallerStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/41_server_streaming_headers_and_negative_test_pb.bal b/ballerina-tests/tests/41_server_streaming_headers_and_negative_test_pb.bal
index 9a91802d2..5f88e8c48 100644
--- a/ballerina-tests/tests/41_server_streaming_headers_and_negative_test_pb.bal
+++ b/ballerina-tests/tests/41_server_streaming_headers_and_negative_test_pb.bal
@@ -92,8 +92,8 @@ public isolated client class Chat41Client {
     }
 }
 
-public client class Chat41StringCaller {
-    private grpc:Caller caller;
+public isolated client class Chat41StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/42_repeated_data_types_test_pb.bal b/ballerina-tests/tests/42_repeated_data_types_test_pb.bal
index 36cdbb69b..2988ec3a7 100644
--- a/ballerina-tests/tests/42_repeated_data_types_test_pb.bal
+++ b/ballerina-tests/tests/42_repeated_data_types_test_pb.bal
@@ -571,8 +571,8 @@ public class BytesArrMsgStream {
     }
 }
 
-public client class DataTypesServiceInt64ArrMsgCaller {
-    private grpc:Caller caller;
+public isolated client class DataTypesServiceInt64ArrMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -603,8 +603,8 @@ public client class DataTypesServiceInt64ArrMsgCaller {
     }
 }
 
-public client class DataTypesServiceInt32ArrMsgCaller {
-    private grpc:Caller caller;
+public isolated client class DataTypesServiceInt32ArrMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -635,8 +635,8 @@ public client class DataTypesServiceInt32ArrMsgCaller {
     }
 }
 
-public client class DataTypesServiceBytesArrMsgCaller {
-    private grpc:Caller caller;
+public isolated client class DataTypesServiceBytesArrMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -667,8 +667,8 @@ public client class DataTypesServiceBytesArrMsgCaller {
     }
 }
 
-public client class DataTypesServiceStringArrMsgCaller {
-    private grpc:Caller caller;
+public isolated client class DataTypesServiceStringArrMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -699,8 +699,8 @@ public client class DataTypesServiceStringArrMsgCaller {
     }
 }
 
-public client class DataTypesServiceFixed32ArrMsgCaller {
-    private grpc:Caller caller;
+public isolated client class DataTypesServiceFixed32ArrMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -731,8 +731,8 @@ public client class DataTypesServiceFixed32ArrMsgCaller {
     }
 }
 
-public client class DataTypesServiceFixed64ArrMsgCaller {
-    private grpc:Caller caller;
+public isolated client class DataTypesServiceFixed64ArrMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -763,8 +763,8 @@ public client class DataTypesServiceFixed64ArrMsgCaller {
     }
 }
 
-public client class DataTypesServiceUnsignedInt64ArrMsgCaller {
-    private grpc:Caller caller;
+public isolated client class DataTypesServiceUnsignedInt64ArrMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -795,8 +795,8 @@ public client class DataTypesServiceUnsignedInt64ArrMsgCaller {
     }
 }
 
-public client class DataTypesServiceFloatArrMsgCaller {
-    private grpc:Caller caller;
+public isolated client class DataTypesServiceFloatArrMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -827,8 +827,8 @@ public client class DataTypesServiceFloatArrMsgCaller {
     }
 }
 
-public client class DataTypesServiceBooleanArrMsgCaller {
-    private grpc:Caller caller;
+public isolated client class DataTypesServiceBooleanArrMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -859,8 +859,8 @@ public client class DataTypesServiceBooleanArrMsgCaller {
     }
 }
 
-public client class DataTypesServiceDoubleArrMsgCaller {
-    private grpc:Caller caller;
+public isolated client class DataTypesServiceDoubleArrMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/43_nested_record_with_streams_pb.bal b/ballerina-tests/tests/43_nested_record_with_streams_pb.bal
index 450d48dfa..f84786476 100644
--- a/ballerina-tests/tests/43_nested_record_with_streams_pb.bal
+++ b/ballerina-tests/tests/43_nested_record_with_streams_pb.bal
@@ -99,8 +99,8 @@ public isolated client class NestedMsgServiceClient {
     }
 }
 
-public client class NestedMsgClientStreamingStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class NestedMsgClientStreamingStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -167,8 +167,8 @@ public class NestedMsgStream {
     }
 }
 
-public client class NestedMsgBidirectionalStreamingStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class NestedMsgBidirectionalStreamingStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -211,8 +211,8 @@ public client class NestedMsgBidirectionalStreamingStreamingClient {
     }
 }
 
-public client class NestedMsgServiceStringCaller {
-    private grpc:Caller caller;
+public isolated client class NestedMsgServiceStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -243,8 +243,8 @@ public client class NestedMsgServiceStringCaller {
     }
 }
 
-public client class NestedMsgServiceNestedMsgCaller {
-    private grpc:Caller caller;
+public isolated client class NestedMsgServiceNestedMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/44_route_guide_pb.bal b/ballerina-tests/tests/44_route_guide_pb.bal
index 1037c4482..3c03066bd 100644
--- a/ballerina-tests/tests/44_route_guide_pb.bal
+++ b/ballerina-tests/tests/44_route_guide_pb.bal
@@ -98,8 +98,8 @@ public isolated client class RouteGuideClient {
     }
 }
 
-public client class RecordRouteStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RecordRouteStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -166,8 +166,8 @@ public class FeatureStream {
     }
 }
 
-public client class RouteChatStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RouteChatStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -210,8 +210,8 @@ public client class RouteChatStreamingClient {
     }
 }
 
-public client class RouteGuideRouteSummaryCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteSummaryCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -242,8 +242,8 @@ public client class RouteGuideRouteSummaryCaller {
     }
 }
 
-public client class RouteGuideRouteNoteCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteNoteCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -274,8 +274,8 @@ public client class RouteGuideRouteNoteCaller {
     }
 }
 
-public client class RouteGuideFeatureCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideFeatureCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/45_services_with_headers_pb.bal b/ballerina-tests/tests/45_services_with_headers_pb.bal
index 8d843a948..42e371f11 100644
--- a/ballerina-tests/tests/45_services_with_headers_pb.bal
+++ b/ballerina-tests/tests/45_services_with_headers_pb.bal
@@ -98,8 +98,8 @@ public isolated client class HeadersServiceClient {
     }
 }
 
-public client class ClientStrStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ClientStrStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -166,8 +166,8 @@ public class HSResStream {
     }
 }
 
-public client class BidirectionalStrStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class BidirectionalStrStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -210,8 +210,8 @@ public client class BidirectionalStrStreamingClient {
     }
 }
 
-public client class HeadersServiceHSResCaller {
-    private grpc:Caller caller;
+public isolated client class HeadersServiceHSResCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/46_empty_values_pb.bal b/ballerina-tests/tests/46_empty_values_pb.bal
index 5324c0bf9..4646232a5 100644
--- a/ballerina-tests/tests/46_empty_values_pb.bal
+++ b/ballerina-tests/tests/46_empty_values_pb.bal
@@ -69,8 +69,8 @@ public isolated client class EmptyHandlerClient {
     }
 }
 
-public client class ClientStrWithEmptyStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ClientStrWithEmptyStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -112,8 +112,8 @@ public client class ClientStrWithEmptyStreamingClient {
     }
 }
 
-public client class EmptyHandlerNilCaller {
-    private grpc:Caller caller;
+public isolated client class EmptyHandlerNilCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -136,8 +136,8 @@ public client class EmptyHandlerNilCaller {
     }
 }
 
-public client class EmptyHandlerStringCaller {
-    private grpc:Caller caller;
+public isolated client class EmptyHandlerStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/47_unary_timestamp_pb.bal b/ballerina-tests/tests/47_unary_timestamp_pb.bal
index 6b65d89ef..0b0c617d3 100644
--- a/ballerina-tests/tests/47_unary_timestamp_pb.bal
+++ b/ballerina-tests/tests/47_unary_timestamp_pb.bal
@@ -153,8 +153,8 @@ public isolated client class TimestampServiceClient {
     }
 }
 
-public client class ClientStreamTimeStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ClientStreamTimeStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -197,8 +197,8 @@ public client class ClientStreamTimeStreamingClient {
     }
 }
 
-public client class TimestampServiceTimestampCaller {
-    private grpc:Caller caller;
+public isolated client class TimestampServiceTimestampCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -229,8 +229,8 @@ public client class TimestampServiceTimestampCaller {
     }
 }
 
-public client class TimestampServiceGreetingCaller {
-    private grpc:Caller caller;
+public isolated client class TimestampServiceGreetingCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/48_bidi_timestamp_pb.bal b/ballerina-tests/tests/48_bidi_timestamp_pb.bal
index 7ba4134ed..8b66609d2 100644
--- a/ballerina-tests/tests/48_bidi_timestamp_pb.bal
+++ b/ballerina-tests/tests/48_bidi_timestamp_pb.bal
@@ -48,8 +48,8 @@ public isolated client class BidiStreamingTimestampServiceClient {
     }
 }
 
-public client class BidiStreamingGreetServerStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class BidiStreamingGreetServerStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -92,8 +92,8 @@ public client class BidiStreamingGreetServerStreamingClient {
     }
 }
 
-public client class BidiStreamingGreetBothStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class BidiStreamingGreetBothStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -136,8 +136,8 @@ public client class BidiStreamingGreetBothStreamingClient {
     }
 }
 
-public client class BidiStreamingExchangeTimeStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class BidiStreamingExchangeTimeStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -180,8 +180,8 @@ public client class BidiStreamingExchangeTimeStreamingClient {
     }
 }
 
-public client class BidiStreamingTimestampServiceTimestampCaller {
-    private grpc:Caller caller;
+public isolated client class BidiStreamingTimestampServiceTimestampCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -212,8 +212,8 @@ public client class BidiStreamingTimestampServiceTimestampCaller {
     }
 }
 
-public client class BidiStreamingTimestampServiceBiDiGreetingCaller {
-    private grpc:Caller caller;
+public isolated client class BidiStreamingTimestampServiceBiDiGreetingCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/49_duration_pb.bal b/ballerina-tests/tests/49_duration_pb.bal
index 5983da056..3f160c04b 100644
--- a/ballerina-tests/tests/49_duration_pb.bal
+++ b/ballerina-tests/tests/49_duration_pb.bal
@@ -130,8 +130,8 @@ public isolated client class DurationHandlerClient {
     }
 }
 
-public client class ClientStreamingStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ClientStreamingStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -174,8 +174,8 @@ public client class ClientStreamingStreamingClient {
     }
 }
 
-public client class BidirectionalStreamingStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class BidirectionalStreamingStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -218,8 +218,8 @@ public client class BidirectionalStreamingStreamingClient {
     }
 }
 
-public client class DurationHandlerDurationMsgCaller {
-    private grpc:Caller caller;
+public isolated client class DurationHandlerDurationMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -250,8 +250,8 @@ public client class DurationHandlerDurationMsgCaller {
     }
 }
 
-public client class DurationHandlerDurationCaller {
-    private grpc:Caller caller;
+public isolated client class DurationHandlerDurationCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -282,8 +282,8 @@ public client class DurationHandlerDurationCaller {
     }
 }
 
-public client class DurationHandlerStringCaller {
-    private grpc:Caller caller;
+public isolated client class DurationHandlerStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/50_bidi_caller_cancel_status_pb.bal b/ballerina-tests/tests/50_bidi_caller_cancel_status_pb.bal
index 66cf8030d..cb344af3f 100644
--- a/ballerina-tests/tests/50_bidi_caller_cancel_status_pb.bal
+++ b/ballerina-tests/tests/50_bidi_caller_cancel_status_pb.bal
@@ -52,8 +52,8 @@ public isolated client class HelloWorld50Client {
     }
 }
 
-public client class SendStringStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class SendStringStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -96,8 +96,8 @@ public client class SendStringStreamingClient {
     }
 }
 
-public client class HelloWorld50BooleanCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld50BooleanCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -128,8 +128,8 @@ public client class HelloWorld50BooleanCaller {
     }
 }
 
-public client class HelloWorld50StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld50StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/51_client_function_utils_negative_cases_pb.bal b/ballerina-tests/tests/51_client_function_utils_negative_cases_pb.bal
index 1f7f83f8e..35b6ffb27 100644
--- a/ballerina-tests/tests/51_client_function_utils_negative_cases_pb.bal
+++ b/ballerina-tests/tests/51_client_function_utils_negative_cases_pb.bal
@@ -99,8 +99,8 @@ public isolated client class HelloWorld51Client {
     }
 }
 
-public client class StringClientStreamingStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class StringClientStreamingStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -143,8 +143,8 @@ public client class StringClientStreamingStreamingClient {
     }
 }
 
-public client class StringBiDiStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class StringBiDiStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -187,8 +187,8 @@ public client class StringBiDiStreamingClient {
     }
 }
 
-public client class HelloWorld51StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld51StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/52_unary_ldap_auth_pb.bal b/ballerina-tests/tests/52_unary_ldap_auth_pb.bal
index 1e1e4f293..52de9775a 100644
--- a/ballerina-tests/tests/52_unary_ldap_auth_pb.bal
+++ b/ballerina-tests/tests/52_unary_ldap_auth_pb.bal
@@ -58,8 +58,8 @@ public isolated client class HelloWorld52Client {
     }
 }
 
-public client class HelloWorld52StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld52StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/53_server_streaming_negative_pb.bal b/ballerina-tests/tests/53_server_streaming_negative_pb.bal
index 2adaad3b4..1717759d5 100644
--- a/ballerina-tests/tests/53_server_streaming_negative_pb.bal
+++ b/ballerina-tests/tests/53_server_streaming_negative_pb.bal
@@ -61,8 +61,8 @@ public isolated client class HelloWorld53Client {
     }
 }
 
-public client class HelloWorld53StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld53StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/54_backward_compatible_client_proto_pb.bal b/ballerina-tests/tests/54_backward_compatible_client_proto_pb.bal
index 55ad7c24d..78f6d35a9 100644
--- a/ballerina-tests/tests/54_backward_compatible_client_proto_pb.bal
+++ b/ballerina-tests/tests/54_backward_compatible_client_proto_pb.bal
@@ -84,8 +84,8 @@ public isolated client class ProductCatalogClient {
     }
 }
 
-public client class ProductCatalogStringCaller {
-    private grpc:Caller caller;
+public isolated client class ProductCatalogStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -116,8 +116,8 @@ public client class ProductCatalogStringCaller {
     }
 }
 
-public client class ProductCatalogProductCaller {
-    private grpc:Caller caller;
+public isolated client class ProductCatalogProductCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/55_declarative_authentication_pb.bal b/ballerina-tests/tests/55_declarative_authentication_pb.bal
index 3b96e2ff6..3ece984f1 100644
--- a/ballerina-tests/tests/55_declarative_authentication_pb.bal
+++ b/ballerina-tests/tests/55_declarative_authentication_pb.bal
@@ -171,8 +171,8 @@ public isolated client class HelloWorld55EmptyScopeClient {
     }
 }
 
-public client class Hello55ClientStreamingStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Hello55ClientStreamingStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -215,8 +215,8 @@ public client class Hello55ClientStreamingStreamingClient {
     }
 }
 
-public client class Hello55BiDiWithCallerStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Hello55BiDiWithCallerStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -259,8 +259,8 @@ public client class Hello55BiDiWithCallerStreamingClient {
     }
 }
 
-public client class Hello55BiDiWithReturnStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Hello55BiDiWithReturnStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -303,8 +303,8 @@ public client class Hello55BiDiWithReturnStreamingClient {
     }
 }
 
-public client class HelloWorld55StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld55StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -335,8 +335,8 @@ public client class HelloWorld55StringCaller {
     }
 }
 
-public client class HelloWorld55EmptyScopeStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld55EmptyScopeStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/56_service_panic_after_send_error_pb.bal b/ballerina-tests/tests/56_service_panic_after_send_error_pb.bal
index 57a00735a..de0ac0bde 100644
--- a/ballerina-tests/tests/56_service_panic_after_send_error_pb.bal
+++ b/ballerina-tests/tests/56_service_panic_after_send_error_pb.bal
@@ -63,8 +63,8 @@ public isolated client class HelloWorld56Client {
     }
 }
 
-public client class Hello56BiDiStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Hello56BiDiStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -107,8 +107,8 @@ public client class Hello56BiDiStreamingClient {
     }
 }
 
-public client class HelloWorld56StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld56StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/57_struct_type_pb.bal b/ballerina-tests/tests/57_struct_type_pb.bal
index f4ebc6008..d64086b3c 100644
--- a/ballerina-tests/tests/57_struct_type_pb.bal
+++ b/ballerina-tests/tests/57_struct_type_pb.bal
@@ -281,8 +281,8 @@ public isolated client class StructServiceClient {
     }
 }
 
-public client class ClientStreamStructType1StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ClientStreamStructType1StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -325,8 +325,8 @@ public client class ClientStreamStructType1StreamingClient {
     }
 }
 
-public client class ClientStreamStructType2StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ClientStreamStructType2StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -393,8 +393,8 @@ public class StructMsgStream {
     }
 }
 
-public client class BidirectionalStreamStructType1StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class BidirectionalStreamStructType1StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -437,8 +437,8 @@ public client class BidirectionalStreamStructType1StreamingClient {
     }
 }
 
-public client class BidirectionalStreamStructType2StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class BidirectionalStreamStructType2StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -481,8 +481,8 @@ public client class BidirectionalStreamStructType2StreamingClient {
     }
 }
 
-public client class StructServiceStructMsgCaller {
-    private grpc:Caller caller;
+public isolated client class StructServiceStructMsgCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -513,8 +513,8 @@ public client class StructServiceStructMsgCaller {
     }
 }
 
-public client class StructServiceStructCaller {
-    private grpc:Caller caller;
+public isolated client class StructServiceStructCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -545,8 +545,8 @@ public client class StructServiceStructCaller {
     }
 }
 
-public client class StructServiceStringCaller {
-    private grpc:Caller caller;
+public isolated client class StructServiceStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/58_nested_message_nested_enum_pb.bal b/ballerina-tests/tests/58_nested_message_nested_enum_pb.bal
index cc3ae7963..b2a757b01 100644
--- a/ballerina-tests/tests/58_nested_message_nested_enum_pb.bal
+++ b/ballerina-tests/tests/58_nested_message_nested_enum_pb.bal
@@ -86,8 +86,8 @@ public isolated client class helloWorldWithNestedMessageNestedEnumClient {
     }
 }
 
-public client class HelloWorldWithNestedMessageNestedEnumByeResponse58Caller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldWithNestedMessageNestedEnumByeResponse58Caller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -118,8 +118,8 @@ public client class HelloWorldWithNestedMessageNestedEnumByeResponse58Caller {
     }
 }
 
-public client class HelloWorldWithNestedMessageNestedEnumHelloResponse58Caller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldWithNestedMessageNestedEnumHelloResponse58Caller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/59_simple_rpc_with_go_service_pb.bal b/ballerina-tests/tests/59_simple_rpc_with_go_service_pb.bal
index 82c066867..e455d117f 100644
--- a/ballerina-tests/tests/59_simple_rpc_with_go_service_pb.bal
+++ b/ballerina-tests/tests/59_simple_rpc_with_go_service_pb.bal
@@ -98,8 +98,8 @@ public isolated client class ProductInfoClient {
     }
 }
 
-public client class ProductInfoProductIDCaller {
-    private grpc:Caller caller;
+public isolated client class ProductInfoProductIDCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -130,8 +130,8 @@ public client class ProductInfoProductIDCaller {
     }
 }
 
-public client class ProductInfoRepeatedTypesCaller {
-    private grpc:Caller caller;
+public isolated client class ProductInfoRepeatedTypesCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -162,8 +162,8 @@ public client class ProductInfoRepeatedTypesCaller {
     }
 }
 
-public client class ProductInfoProductDetailCaller {
-    private grpc:Caller caller;
+public isolated client class ProductInfoProductDetailCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/60_client_send_error_in_client_bidi_streaming_pb.bal b/ballerina-tests/tests/60_client_send_error_in_client_bidi_streaming_pb.bal
index 7e987f54e..8068504a5 100644
--- a/ballerina-tests/tests/60_client_send_error_in_client_bidi_streaming_pb.bal
+++ b/ballerina-tests/tests/60_client_send_error_in_client_bidi_streaming_pb.bal
@@ -40,8 +40,8 @@ public isolated client class ErrorSendServiceClient {
     }
 }
 
-public client class SendErrorClientStreamingStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class SendErrorClientStreamingStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -84,8 +84,8 @@ public client class SendErrorClientStreamingStreamingClient {
     }
 }
 
-public client class SendErrorBidiStreamingStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class SendErrorBidiStreamingStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -128,8 +128,8 @@ public client class SendErrorBidiStreamingStreamingClient {
     }
 }
 
-public client class ErrorSendServiceIntCaller {
-    private grpc:Caller caller;
+public isolated client class ErrorSendServiceIntCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/61_any_type_pb.bal b/ballerina-tests/tests/61_any_type_pb.bal
index f9125649f..0cad64b76 100644
--- a/ballerina-tests/tests/61_any_type_pb.bal
+++ b/ballerina-tests/tests/61_any_type_pb.bal
@@ -156,8 +156,8 @@ public isolated client class AnyTypeServerClient {
     }
 }
 
-public client class ClientStreamingCallStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ClientStreamingCallStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -200,8 +200,8 @@ public client class ClientStreamingCallStreamingClient {
     }
 }
 
-public client class BidirectionalStreamingCallStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class BidirectionalStreamingCallStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -244,8 +244,8 @@ public client class BidirectionalStreamingCallStreamingClient {
     }
 }
 
-public client class AnyTypeServerAnyCaller {
-    private grpc:Caller caller;
+public isolated client class AnyTypeServerAnyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/62_message_size_pb.bal b/ballerina-tests/tests/62_message_size_pb.bal
index 471fd03b9..116752dfd 100644
--- a/ballerina-tests/tests/62_message_size_pb.bal
+++ b/ballerina-tests/tests/62_message_size_pb.bal
@@ -99,8 +99,8 @@ public isolated client class HelloWorld62Client {
     }
 }
 
-public client class MsgSizeClientStreamingStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class MsgSizeClientStreamingStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -143,8 +143,8 @@ public client class MsgSizeClientStreamingStreamingClient {
     }
 }
 
-public client class MsgSizeBidiStreamingStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class MsgSizeBidiStreamingStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -187,8 +187,8 @@ public client class MsgSizeBidiStreamingStreamingClient {
     }
 }
 
-public client class HelloWorld62StringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld62StringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/63_enum_with_reserved_names_pb.bal b/ballerina-tests/tests/63_enum_with_reserved_names_pb.bal
index 6417256f9..0dea737ba 100644
--- a/ballerina-tests/tests/63_enum_with_reserved_names_pb.bal
+++ b/ballerina-tests/tests/63_enum_with_reserved_names_pb.bal
@@ -58,8 +58,8 @@ public isolated client class MessageServiceClient {
     }
 }
 
-public client class MessageServiceMessageStateCaller {
-    private grpc:Caller caller;
+public isolated client class MessageServiceMessageStateCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/64_predefined_records_pb.bal b/ballerina-tests/tests/64_predefined_records_pb.bal
index 750207723..361421dbc 100644
--- a/ballerina-tests/tests/64_predefined_records_pb.bal
+++ b/ballerina-tests/tests/64_predefined_records_pb.bal
@@ -164,8 +164,8 @@ public isolated client class PredefinedRecordsClient {
     }
 }
 
-public client class PredefinedRecordsTimestampCaller {
-    private grpc:Caller caller;
+public isolated client class PredefinedRecordsTimestampCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -196,8 +196,8 @@ public client class PredefinedRecordsTimestampCaller {
     }
 }
 
-public client class PredefinedRecordsEmptyCaller {
-    private grpc:Caller caller;
+public isolated client class PredefinedRecordsEmptyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -228,8 +228,8 @@ public client class PredefinedRecordsEmptyCaller {
     }
 }
 
-public client class PredefinedRecordsStructCaller {
-    private grpc:Caller caller;
+public isolated client class PredefinedRecordsStructCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -260,8 +260,8 @@ public client class PredefinedRecordsStructCaller {
     }
 }
 
-public client class PredefinedRecordsDurationCaller {
-    private grpc:Caller caller;
+public isolated client class PredefinedRecordsDurationCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -292,8 +292,8 @@ public client class PredefinedRecordsDurationCaller {
     }
 }
 
-public client class PredefinedRecordsAnyCaller {
-    private grpc:Caller caller;
+public isolated client class PredefinedRecordsAnyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/65_repeated_types_pb.bal b/ballerina-tests/tests/65_repeated_types_pb.bal
index 7278fce7c..2ba355063 100644
--- a/ballerina-tests/tests/65_repeated_types_pb.bal
+++ b/ballerina-tests/tests/65_repeated_types_pb.bal
@@ -144,8 +144,8 @@ public isolated client class RepeatedTypesServiceClient {
     }
 }
 
-public client class RepeatedTypesServiceDurationArrayResponseCaller {
-    private grpc:Caller caller;
+public isolated client class RepeatedTypesServiceDurationArrayResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -176,8 +176,8 @@ public client class RepeatedTypesServiceDurationArrayResponseCaller {
     }
 }
 
-public client class RepeatedTypesServiceTimestampArrayResponseCaller {
-    private grpc:Caller caller;
+public isolated client class RepeatedTypesServiceTimestampArrayResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -208,8 +208,8 @@ public client class RepeatedTypesServiceTimestampArrayResponseCaller {
     }
 }
 
-public client class RepeatedTypesServiceAnyArrayResponseCaller {
-    private grpc:Caller caller;
+public isolated client class RepeatedTypesServiceAnyArrayResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -240,8 +240,8 @@ public client class RepeatedTypesServiceAnyArrayResponseCaller {
     }
 }
 
-public client class RepeatedTypesServiceStructArrayResponseCaller {
-    private grpc:Caller caller;
+public isolated client class RepeatedTypesServiceStructArrayResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/66_predefined_types_in_messages_pb.bal b/ballerina-tests/tests/66_predefined_types_in_messages_pb.bal
index a81d61c84..599a1640e 100644
--- a/ballerina-tests/tests/66_predefined_types_in_messages_pb.bal
+++ b/ballerina-tests/tests/66_predefined_types_in_messages_pb.bal
@@ -144,8 +144,8 @@ public isolated client class PredefinedTypesInServiceClient {
     }
 }
 
-public client class PredefinedTypesInServiceStructMessageResponseCaller {
-    private grpc:Caller caller;
+public isolated client class PredefinedTypesInServiceStructMessageResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -176,8 +176,8 @@ public client class PredefinedTypesInServiceStructMessageResponseCaller {
     }
 }
 
-public client class PredefinedTypesInServiceTimestampMessageResponseCaller {
-    private grpc:Caller caller;
+public isolated client class PredefinedTypesInServiceTimestampMessageResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -208,8 +208,8 @@ public client class PredefinedTypesInServiceTimestampMessageResponseCaller {
     }
 }
 
-public client class PredefinedTypesInServiceAnyMessageResponseCaller {
-    private grpc:Caller caller;
+public isolated client class PredefinedTypesInServiceAnyMessageResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -240,8 +240,8 @@ public client class PredefinedTypesInServiceAnyMessageResponseCaller {
     }
 }
 
-public client class PredefinedTypesInServiceDurationMessageResponseCaller {
-    private grpc:Caller caller;
+public isolated client class PredefinedTypesInServiceDurationMessageResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/67_simple_service_with_annotation_pb.bal b/ballerina-tests/tests/67_simple_service_with_annotation_pb.bal
index 8f98c1ed5..d0978c568 100644
--- a/ballerina-tests/tests/67_simple_service_with_annotation_pb.bal
+++ b/ballerina-tests/tests/67_simple_service_with_annotation_pb.bal
@@ -97,8 +97,8 @@ public isolated client class SimpleServiceWithAnnotationClient {
     }
 }
 
-public client class ClientStreamingWithAnnotatedDataStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ClientStreamingWithAnnotatedDataStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -165,8 +165,8 @@ public class SimpleResponseWithAnnotationStream {
     }
 }
 
-public client class BidirectionalStreamingWithAnnotatedDataStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class BidirectionalStreamingWithAnnotatedDataStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -209,8 +209,8 @@ public client class BidirectionalStreamingWithAnnotatedDataStreamingClient {
     }
 }
 
-public client class SimpleServiceWithAnnotationSimpleResponseWithAnnotationCaller {
-    private grpc:Caller caller;
+public isolated client class SimpleServiceWithAnnotationSimpleResponseWithAnnotationCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/68_service_with_descriptor_annotation_pb.bal b/ballerina-tests/tests/68_service_with_descriptor_annotation_pb.bal
index efe13cd39..0ddda5c66 100644
--- a/ballerina-tests/tests/68_service_with_descriptor_annotation_pb.bal
+++ b/ballerina-tests/tests/68_service_with_descriptor_annotation_pb.bal
@@ -35,8 +35,8 @@ public isolated client class helloDescriptorAnnotationClient {
     }
 }
 
-public client class HelloStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class HelloStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -79,8 +79,8 @@ public client class HelloStreamingClient {
     }
 }
 
-public client class HelloDescriptorAnnotationStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloDescriptorAnnotationStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/72_service_with_updated_proto_definition_client_pb.bal b/ballerina-tests/tests/72_service_with_updated_proto_definition_client_pb.bal
index 89f17eb0a..07831a717 100644
--- a/ballerina-tests/tests/72_service_with_updated_proto_definition_client_pb.bal
+++ b/ballerina-tests/tests/72_service_with_updated_proto_definition_client_pb.bal
@@ -59,8 +59,8 @@ public isolated client class UpdatedServiceClient {
     }
 }
 
-public client class UpdatedServiceGetClassResponseCaller {
-    private grpc:Caller caller;
+public isolated client class UpdatedServiceGetClassResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -91,8 +91,8 @@ public client class UpdatedServiceGetClassResponseCaller {
     }
 }
 
-public client class UpdatedServiceGroupCaller {
-    private grpc:Caller caller;
+public isolated client class UpdatedServiceGroupCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/73_streaming_with_depending_message_pb.bal b/ballerina-tests/tests/73_streaming_with_depending_message_pb.bal
index ba64cb7de..0ea0fe8ce 100644
--- a/ballerina-tests/tests/73_streaming_with_depending_message_pb.bal
+++ b/ballerina-tests/tests/73_streaming_with_depending_message_pb.bal
@@ -98,8 +98,8 @@ public isolated client class HelloWorld73Client {
     }
 }
 
-public client class Hello73ClientStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Hello73ClientStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -166,8 +166,8 @@ public class ReplyMessageStream {
     }
 }
 
-public client class Hello73BidiStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Hello73BidiStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -210,8 +210,8 @@ public client class Hello73BidiStreamingClient {
     }
 }
 
-public client class HelloWorld73ReplyMessageCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorld73ReplyMessageCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/74_75_reflection_pb.bal b/ballerina-tests/tests/74_75_reflection_pb.bal
index ab729e362..4f07c2393 100644
--- a/ballerina-tests/tests/74_75_reflection_pb.bal
+++ b/ballerina-tests/tests/74_75_reflection_pb.bal
@@ -35,8 +35,8 @@ public isolated client class ServerReflectionClient {
     }
 }
 
-public client class ServerReflectionInfoStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ServerReflectionInfoStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -79,8 +79,8 @@ public client class ServerReflectionInfoStreamingClient {
     }
 }
 
-public client class ServerReflectionServerReflectionResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ServerReflectionServerReflectionResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/76_number_types_pb.bal b/ballerina-tests/tests/76_number_types_pb.bal
index dedffd644..27f83b0b1 100644
--- a/ballerina-tests/tests/76_number_types_pb.bal
+++ b/ballerina-tests/tests/76_number_types_pb.bal
@@ -199,8 +199,8 @@ public isolated client class TypesServiceClient {
     }
 }
 
-public client class TypesServiceRepeatedTypesMessageCaller {
-    private grpc:Caller caller;
+public isolated client class TypesServiceRepeatedTypesMessageCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -231,8 +231,8 @@ public client class TypesServiceRepeatedTypesMessageCaller {
     }
 }
 
-public client class TypesServiceTypesMessageCaller {
-    private grpc:Caller caller;
+public isolated client class TypesServiceTypesMessageCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -263,8 +263,8 @@ public client class TypesServiceTypesMessageCaller {
     }
 }
 
-public client class TypesServiceIntCaller {
-    private grpc:Caller caller;
+public isolated client class TypesServiceIntCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/77_enum_imports_child_pb.bal b/ballerina-tests/tests/77_enum_imports_child_pb.bal
index ec80aac67..258bb8fcd 100644
--- a/ballerina-tests/tests/77_enum_imports_child_pb.bal
+++ b/ballerina-tests/tests/77_enum_imports_child_pb.bal
@@ -60,8 +60,8 @@ public isolated client class LocationServiceClient {
     }
 }
 
-public client class LocationServiceLocationDetailCaller {
-    private grpc:Caller caller;
+public isolated client class LocationServiceLocationDetailCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina-tests/tests/78_server_error_types_pb.bal b/ballerina-tests/tests/78_server_error_types_pb.bal
index 2c3c1a776..1dd8b3685 100644
--- a/ballerina-tests/tests/78_server_error_types_pb.bal
+++ b/ballerina-tests/tests/78_server_error_types_pb.bal
@@ -57,8 +57,8 @@ public isolated client class ServerErrorTypesServiceClient {
     }
 }
 
-public client class ServerErrorTypesServiceNilCaller {
-    private grpc:Caller caller;
+public isolated client class ServerErrorTypesServiceNilCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/ballerina/Ballerina.toml b/ballerina/Ballerina.toml
index a1d341a86..85cb092ff 100644
--- a/ballerina/Ballerina.toml
+++ b/ballerina/Ballerina.toml
@@ -1,7 +1,7 @@
 [package]
 org = "ballerina"
 name = "grpc"
-version = "1.11.0"
+version = "1.11.1"
 distribution = "2201.9.0"
 authors = ["Ballerina"]
 keywords = ["network", "grpc", "protobuf", "server-streaming", "client-streaming", "bidirectional-streaming"]
@@ -16,11 +16,11 @@ graalvmCompatible = true
 [[platform.java17.dependency]]
 groupId = "io.ballerina.stdlib"
 artifactId = "grpc-native"
-version = "1.11.0"
-path = "../native/build/libs/grpc-native-1.11.0.jar"
+version = "1.11.1"
+path = "../native/build/libs/grpc-native-1.11.1-SNAPSHOT.jar"
 
 [[platform.java17.dependency]]
-path = "../test-utils/build/libs/grpc-test-utils-1.11.0.jar"
+path = "../test-utils/build/libs/grpc-test-utils-1.11.1-SNAPSHOT.jar"
 scope = "testOnly"
 
 [[platform.java17.dependency]]
diff --git a/ballerina/CompilerPlugin.toml b/ballerina/CompilerPlugin.toml
index dffd4e63f..43cbf1b7e 100644
--- a/ballerina/CompilerPlugin.toml
+++ b/ballerina/CompilerPlugin.toml
@@ -3,4 +3,4 @@ id = "grpc-compiler-plugin"
 class = "io.ballerina.stdlib.grpc.plugin.GrpcCompilerPlugin"
 
 [[dependency]]
-path = "../compiler-plugin/build/libs/grpc-compiler-plugin-1.11.0.jar"
+path = "../compiler-plugin/build/libs/grpc-compiler-plugin-1.11.1-SNAPSHOT.jar"
diff --git a/ballerina/Dependencies.toml b/ballerina/Dependencies.toml
index 2c72f6e72..8398f987a 100644
--- a/ballerina/Dependencies.toml
+++ b/ballerina/Dependencies.toml
@@ -44,7 +44,7 @@ dependencies = [
 [[package]]
 org = "ballerina"
 name = "crypto"
-version = "2.7.0"
+version = "2.7.2"
 dependencies = [
 	{org = "ballerina", name = "jballerina.java"},
 	{org = "ballerina", name = "time"}
@@ -68,7 +68,7 @@ dependencies = [
 [[package]]
 org = "ballerina"
 name = "grpc"
-version = "1.11.0"
+version = "1.11.1"
 dependencies = [
 	{org = "ballerina", name = "auth"},
 	{org = "ballerina", name = "crypto"},
@@ -94,7 +94,7 @@ modules = [
 [[package]]
 org = "ballerina"
 name = "http"
-version = "2.11.0"
+version = "2.11.2"
 scope = "testOnly"
 dependencies = [
 	{org = "ballerina", name = "auth"},
diff --git a/ballerina/caller.bal b/ballerina/caller.bal
index 38500a62c..3e4b6061e 100644
--- a/ballerina/caller.bal
+++ b/ballerina/caller.bal
@@ -19,12 +19,7 @@ import ballerina/jballerina.java;
 # The base client used in the generated client code to provide remote functions for interacting with the caller.
 #
 # + instanceId - The connection ID
-# + remoteDetails - The remote details
-# + local - The local details
-public client class Caller {
-
-    public Remote remoteDetails = {};
-    public Local local = {};
+public isolated client class Caller {
 
     private int instanceId = -1;
 
@@ -35,7 +30,9 @@ public client class Caller {
     #
     # + return - caller ID
     public isolated function getId() returns int {
-        return self.instanceId;
+        lock {
+            return self.instanceId;
+        }
     }
 
     # Sends the outbound response to the caller.
@@ -100,21 +97,3 @@ isolated function externSendError(Caller endpointClient, Error err) returns Erro
 @java:Method {
     'class: "io.ballerina.stdlib.grpc.nativeimpl.caller.FunctionUtils"
 } external;
-
-# Presents a read-only view of the remote address.
-#
-# + host - The remote host name/IP
-# + port - The remote port
-public type Remote record {|
-    string host = "";
-    int port = 0;
-|};
-
-# Presents a read-only view of the local address.
-#
-# + host - The local host name/IP
-# + port - The local port
-public type Local record {|
-    string host = "";
-    int port = 0;
-|};
diff --git a/ballerina/reflection_pb.bal b/ballerina/reflection_pb.bal
index 264402409..09a7684db 100644
--- a/ballerina/reflection_pb.bal
+++ b/ballerina/reflection_pb.bal
@@ -19,8 +19,8 @@ import ballerina/protobuf;
 const string REFLECTION_DESC = "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";
 
 # This is used for internal purposes to support reflection.
-public client class ServerReflectionServerReflectionResponseCaller {
-    private Caller caller;
+public isolated client class ServerReflectionServerReflectionResponseCaller {
+    private final Caller caller;
 
     public isolated function init(Caller caller) {
         self.caller = caller;
diff --git a/ballerina/streaming_client.bal b/ballerina/streaming_client.bal
index 6f34fed6f..af8b71763 100644
--- a/ballerina/streaming_client.bal
+++ b/ballerina/streaming_client.bal
@@ -18,8 +18,8 @@ import ballerina/jballerina.java;
 
 # The base client used in the generated client code to provide the gRPC streaming client actions for
 # interacting  with the gRPC server.
-public client class StreamingClient {
-    stream<anydata, Error?>? serverStream = ();
+public isolated client class StreamingClient {
+    private stream<anydata, Error?>? serverStream = ();
 
     # Sends the request message to the server.
     # ```ballerina
@@ -62,33 +62,35 @@ public client class StreamingClient {
     isolated remote function receive() returns [anydata, map<string|string[]>]|Error? {
         map<string|string[]> headers = {};
         if externIsBidirectional(self) {
-            if self.serverStream is stream<anydata, Error?> {
-                var nextRecord = (<stream<anydata, Error?>>self.serverStream).next();
-                map<string|string[]>? headerMap = externGetHeaderMap(self, true);
-                if headerMap is map<string|string[]> {
-                    headers = headerMap;
-                }
-                if nextRecord is record {|anydata value;|} {
-                    return [nextRecord.value, headers];
-                } else {
-                    return nextRecord;
-                }
-            } else {
-                anydata|stream<anydata, Error?> result = check externReceive(self);
-                if result is stream<anydata, Error?> {
-                    self.serverStream = result;
+            lock {
+                if self.serverStream is stream<anydata, Error?> {
                     var nextRecord = (<stream<anydata, Error?>>self.serverStream).next();
-                    var headerMap = externGetHeaderMap(self, true);
+                    map<string|string[]>? headerMap = externGetHeaderMap(self, true);
                     if headerMap is map<string|string[]> {
-                        headers = headerMap;
+                        headers = headerMap.clone();
                     }
                     if nextRecord is record {|anydata value;|} {
-                        return [nextRecord.value, headers];
+                        return [nextRecord.value.clone(), headers.clone()];
                     } else {
                         return nextRecord;
                     }
+                } else {
+                    anydata|stream<anydata, Error?> result = check externReceive(self);
+                    if result is stream<anydata, Error?> {
+                        self.serverStream = result;
+                        var nextRecord = (<stream<anydata, Error?>>self.serverStream).next();
+                        var headerMap = externGetHeaderMap(self, true);
+                        if headerMap is map<string|string[]> {
+                            headers = headerMap.clone();
+                        }
+                        if nextRecord is record {|anydata value;|} {
+                            return [nextRecord.value.clone(), headers.clone()];
+                        } else {
+                            return nextRecord;
+                        }
+                    }
+                    return error DataMismatchError("Expected a stream but found an anydata type.");
                 }
-                return error DataMismatchError("Expected a stream but found an anydata type.");
             }
         } else {
             anydata|stream<anydata, Error?> result = check externReceive(self);
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_01/grpc_unary_blocking_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_01/grpc_unary_blocking_pb.bal
index 01ff19827..e5e80d9b3 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_01/grpc_unary_blocking_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_01/grpc_unary_blocking_pb.bal
@@ -60,8 +60,8 @@ public isolated client class HelloWorldClient {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_02/grpc_server_streaming_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_02/grpc_server_streaming_pb.bal
index 2ef74e57e..c6f505ef4 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_02/grpc_server_streaming_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_02/grpc_server_streaming_pb.bal
@@ -71,8 +71,8 @@ public class StringStream {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_03/grpc_server_streaming_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_03/grpc_server_streaming_pb.bal
index 2ef74e57e..c6f505ef4 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_03/grpc_server_streaming_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_03/grpc_server_streaming_pb.bal
@@ -71,8 +71,8 @@ public class StringStream {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_04/grpc_server_streaming_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_04/grpc_server_streaming_pb.bal
index 2ef74e57e..c6f505ef4 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_04/grpc_server_streaming_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_04/grpc_server_streaming_pb.bal
@@ -71,8 +71,8 @@ public class StringStream {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_05/grpc_server_streaming_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_05/grpc_server_streaming_pb.bal
index 2ef74e57e..c6f505ef4 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_05/grpc_server_streaming_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_05/grpc_server_streaming_pb.bal
@@ -71,8 +71,8 @@ public class StringStream {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_06/grpc_server_streaming_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_06/grpc_server_streaming_pb.bal
index 2ef74e57e..c6f505ef4 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_06/grpc_server_streaming_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_06/grpc_server_streaming_pb.bal
@@ -71,8 +71,8 @@ public class StringStream {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_07/grpc_server_streaming_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_07/grpc_server_streaming_pb.bal
index a8e98d218..3ff91b87a 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_07/grpc_server_streaming_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_07/grpc_server_streaming_pb.bal
@@ -71,8 +71,8 @@ public class StringStream {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -98,8 +98,8 @@ public client class HelloWorldStringCaller {
     }
 }
 
-public client class CustomCaller {
-    private grpc:Caller caller;
+public isolated client class CustomCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_08/grpc_server_streaming_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_08/grpc_server_streaming_pb.bal
index 2ef74e57e..c6f505ef4 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_08/grpc_server_streaming_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_08/grpc_server_streaming_pb.bal
@@ -71,8 +71,8 @@ public class StringStream {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_09/grpc_service.bal b/compiler-plugin-tests/src/test/resources/test-src/package_09/grpc_service.bal
index 5741db6b7..c70566892 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_09/grpc_service.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_09/grpc_service.bal
@@ -44,8 +44,8 @@ public type ContextString record {|
     map<string|string[]> headers;
 |};
 
-public client class HelloWStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_10/grpc_service.bal b/compiler-plugin-tests/src/test/resources/test-src/package_10/grpc_service.bal
index c1e04266e..efdd63149 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_10/grpc_service.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_10/grpc_service.bal
@@ -44,8 +44,8 @@ public type ContextString record {|
     map<string|string[]> headers;
 |};
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_11/grpc_service.bal b/compiler-plugin-tests/src/test/resources/test-src/package_11/grpc_service.bal
index f6473ae62..261f8be5c 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_11/grpc_service.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_11/grpc_service.bal
@@ -44,8 +44,8 @@ public type ContextString record {|
     map<string|string[]> headers;
 |};
 
-public client class HelloStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_12/grpc_service.bal b/compiler-plugin-tests/src/test/resources/test-src/package_12/grpc_service.bal
index c1e04266e..efdd63149 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_12/grpc_service.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_12/grpc_service.bal
@@ -44,8 +44,8 @@ public type ContextString record {|
     map<string|string[]> headers;
 |};
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_13/streaming_calc_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_13/streaming_calc_pb.bal
index 1ae3451cc..d490b0e8d 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_13/streaming_calc_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_13/streaming_calc_pb.bal
@@ -16,8 +16,8 @@
 
 import ballerina/grpc;
 
-public client class StreamingCalcServiceIntCaller {
-    private grpc:Caller caller;
+public isolated client class StreamingCalcServiceIntCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_14/grpc_unary_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_14/grpc_unary_pb.bal
index c8514b152..90e82e577 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_14/grpc_unary_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_14/grpc_unary_pb.bal
@@ -95,8 +95,8 @@ public isolated client class HelloBallerinaClient {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -127,8 +127,8 @@ public client class HelloWorldStringCaller {
     }
 }
 
-public client class HelloBallerinaStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloBallerinaStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_15/grpc_unary_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_15/grpc_unary_pb.bal
index c8514b152..90e82e577 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_15/grpc_unary_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_15/grpc_unary_pb.bal
@@ -95,8 +95,8 @@ public isolated client class HelloBallerinaClient {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -127,8 +127,8 @@ public client class HelloWorldStringCaller {
     }
 }
 
-public client class HelloBallerinaStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloBallerinaStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_16/grpc_unary_blocking_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_16/grpc_unary_blocking_pb.bal
index 5e51eecb1..eb69c06e2 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_16/grpc_unary_blocking_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_16/grpc_unary_blocking_pb.bal
@@ -60,8 +60,8 @@ public isolated client class HelloWorldClient {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_17/grpc_unary_blocking_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_17/grpc_unary_blocking_pb.bal
index 5e51eecb1..eb69c06e2 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_17/grpc_unary_blocking_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_17/grpc_unary_blocking_pb.bal
@@ -60,8 +60,8 @@ public isolated client class HelloWorldClient {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_18/helloworld_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_18/helloworld_pb.bal
index 07426a323..775ae7183 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_18/helloworld_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_18/helloworld_pb.bal
@@ -55,8 +55,8 @@ public isolated client class helloWorldClient {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_19/helloworld_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_19/helloworld_pb.bal
index 93519508b..03fbbe4fb 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_19/helloworld_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_19/helloworld_pb.bal
@@ -55,8 +55,8 @@ public isolated client class helloWorldClient {
     }
 }
 
-public client class helloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class helloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_20/helloWorldString_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_20/helloWorldString_pb.bal
index a02a0ce96..04f8899ca 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_20/helloWorldString_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_20/helloWorldString_pb.bal
@@ -19,8 +19,8 @@ public isolated client class helloWorldClient {
     }
 }
 
-public client class HelloStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class HelloStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -63,8 +63,8 @@ public client class HelloStreamingClient {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_21/helloWorldString_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_21/helloWorldString_pb.bal
index f8a76bb98..a8d8a0c39 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_21/helloWorldString_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_21/helloWorldString_pb.bal
@@ -35,8 +35,8 @@ public isolated client class helloWorldClient {
     }
 }
 
-public client class HelloStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class HelloStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -79,8 +79,8 @@ public client class HelloStreamingClient {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_22/helloWorldString_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_22/helloWorldString_pb.bal
index f8a76bb98..a8d8a0c39 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_22/helloWorldString_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_22/helloWorldString_pb.bal
@@ -35,8 +35,8 @@ public isolated client class helloWorldClient {
     }
 }
 
-public client class HelloStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class HelloStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -79,8 +79,8 @@ public client class HelloStreamingClient {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/compiler-plugin-tests/src/test/resources/test-src/package_23/helloWorldString_pb.bal b/compiler-plugin-tests/src/test/resources/test-src/package_23/helloWorldString_pb.bal
index f8a76bb98..a8d8a0c39 100644
--- a/compiler-plugin-tests/src/test/resources/test-src/package_23/helloWorldString_pb.bal
+++ b/compiler-plugin-tests/src/test/resources/test-src/package_23/helloWorldString_pb.bal
@@ -35,8 +35,8 @@ public isolated client class helloWorldClient {
     }
 }
 
-public client class HelloStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class HelloStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -79,8 +79,8 @@ public client class HelloStreamingClient {
     }
 }
 
-public client class HelloWorldStringCaller {
-    private grpc:Caller caller;
+public isolated client class HelloWorldStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/examples/async-streaming/client/phone_pb.bal b/examples/async-streaming/client/phone_pb.bal
index d1c55e0ff..19debdfcd 100644
--- a/examples/async-streaming/client/phone_pb.bal
+++ b/examples/async-streaming/client/phone_pb.bal
@@ -32,8 +32,8 @@ public isolated client class PhoneClient {
     }
 }
 
-public client class StreamCallStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class StreamCallStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -76,8 +76,8 @@ public client class StreamCallStreamingClient {
     }
 }
 
-public client class PhoneStreamCallResponseCaller {
-    private grpc:Caller caller;
+public isolated client class PhoneStreamCallResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/examples/async-streaming/server/phone_pb.bal b/examples/async-streaming/server/phone_pb.bal
index b66a17344..9abbeed48 100644
--- a/examples/async-streaming/server/phone_pb.bal
+++ b/examples/async-streaming/server/phone_pb.bal
@@ -32,8 +32,8 @@ public isolated client class PhoneClient {
     }
 }
 
-public client class StreamCallStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class StreamCallStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -76,8 +76,8 @@ public client class StreamCallStreamingClient {
     }
 }
 
-public client class PhoneStreamCallResponseCaller {
-    private grpc:Caller caller;
+public isolated client class PhoneStreamCallResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/examples/online-boutique-microservice/ad-service/demo_pb.bal b/examples/online-boutique-microservice/ad-service/demo_pb.bal
index a17d95e06..202a3526f 100644
--- a/examples/online-boutique-microservice/ad-service/demo_pb.bal
+++ b/examples/online-boutique-microservice/ad-service/demo_pb.bal
@@ -535,8 +535,8 @@ public isolated client class AdServiceClient {
     }
 }
 
-public client class CartServiceEmptyCaller {
-    private grpc:Caller caller;
+public isolated client class CartServiceEmptyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -567,8 +567,8 @@ public client class CartServiceEmptyCaller {
     }
 }
 
-public client class CartServiceCartCaller {
-    private grpc:Caller caller;
+public isolated client class CartServiceCartCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -599,8 +599,8 @@ public client class CartServiceCartCaller {
     }
 }
 
-public client class RecommendationServiceListRecommendationsResponseCaller {
-    private grpc:Caller caller;
+public isolated client class RecommendationServiceListRecommendationsResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -631,8 +631,8 @@ public client class RecommendationServiceListRecommendationsResponseCaller {
     }
 }
 
-public client class ProductCatalogServiceListProductsResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ProductCatalogServiceListProductsResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -663,8 +663,8 @@ public client class ProductCatalogServiceListProductsResponseCaller {
     }
 }
 
-public client class ProductCatalogServiceSearchProductsResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ProductCatalogServiceSearchProductsResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -695,8 +695,8 @@ public client class ProductCatalogServiceSearchProductsResponseCaller {
     }
 }
 
-public client class ProductCatalogServiceProductCaller {
-    private grpc:Caller caller;
+public isolated client class ProductCatalogServiceProductCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -727,8 +727,8 @@ public client class ProductCatalogServiceProductCaller {
     }
 }
 
-public client class ShippingServiceGetQuoteResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ShippingServiceGetQuoteResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -759,8 +759,8 @@ public client class ShippingServiceGetQuoteResponseCaller {
     }
 }
 
-public client class ShippingServiceShipOrderResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ShippingServiceShipOrderResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -791,8 +791,8 @@ public client class ShippingServiceShipOrderResponseCaller {
     }
 }
 
-public client class CurrencyServiceGetSupportedCurrenciesResponseCaller {
-    private grpc:Caller caller;
+public isolated client class CurrencyServiceGetSupportedCurrenciesResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -823,8 +823,8 @@ public client class CurrencyServiceGetSupportedCurrenciesResponseCaller {
     }
 }
 
-public client class CurrencyServiceMoneyCaller {
-    private grpc:Caller caller;
+public isolated client class CurrencyServiceMoneyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -855,8 +855,8 @@ public client class CurrencyServiceMoneyCaller {
     }
 }
 
-public client class PaymentServiceChargeResponseCaller {
-    private grpc:Caller caller;
+public isolated client class PaymentServiceChargeResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -887,8 +887,8 @@ public client class PaymentServiceChargeResponseCaller {
     }
 }
 
-public client class EmailServiceEmptyCaller {
-    private grpc:Caller caller;
+public isolated client class EmailServiceEmptyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -919,8 +919,8 @@ public client class EmailServiceEmptyCaller {
     }
 }
 
-public client class CheckoutServicePlaceOrderResponseCaller {
-    private grpc:Caller caller;
+public isolated client class CheckoutServicePlaceOrderResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -951,8 +951,8 @@ public client class CheckoutServicePlaceOrderResponseCaller {
     }
 }
 
-public client class AdServiceAdResponseCaller {
-    private grpc:Caller caller;
+public isolated client class AdServiceAdResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/examples/online-boutique-microservice/product-catalog-service/demo_pb.bal b/examples/online-boutique-microservice/product-catalog-service/demo_pb.bal
index a17d95e06..202a3526f 100644
--- a/examples/online-boutique-microservice/product-catalog-service/demo_pb.bal
+++ b/examples/online-boutique-microservice/product-catalog-service/demo_pb.bal
@@ -535,8 +535,8 @@ public isolated client class AdServiceClient {
     }
 }
 
-public client class CartServiceEmptyCaller {
-    private grpc:Caller caller;
+public isolated client class CartServiceEmptyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -567,8 +567,8 @@ public client class CartServiceEmptyCaller {
     }
 }
 
-public client class CartServiceCartCaller {
-    private grpc:Caller caller;
+public isolated client class CartServiceCartCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -599,8 +599,8 @@ public client class CartServiceCartCaller {
     }
 }
 
-public client class RecommendationServiceListRecommendationsResponseCaller {
-    private grpc:Caller caller;
+public isolated client class RecommendationServiceListRecommendationsResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -631,8 +631,8 @@ public client class RecommendationServiceListRecommendationsResponseCaller {
     }
 }
 
-public client class ProductCatalogServiceListProductsResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ProductCatalogServiceListProductsResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -663,8 +663,8 @@ public client class ProductCatalogServiceListProductsResponseCaller {
     }
 }
 
-public client class ProductCatalogServiceSearchProductsResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ProductCatalogServiceSearchProductsResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -695,8 +695,8 @@ public client class ProductCatalogServiceSearchProductsResponseCaller {
     }
 }
 
-public client class ProductCatalogServiceProductCaller {
-    private grpc:Caller caller;
+public isolated client class ProductCatalogServiceProductCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -727,8 +727,8 @@ public client class ProductCatalogServiceProductCaller {
     }
 }
 
-public client class ShippingServiceGetQuoteResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ShippingServiceGetQuoteResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -759,8 +759,8 @@ public client class ShippingServiceGetQuoteResponseCaller {
     }
 }
 
-public client class ShippingServiceShipOrderResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ShippingServiceShipOrderResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -791,8 +791,8 @@ public client class ShippingServiceShipOrderResponseCaller {
     }
 }
 
-public client class CurrencyServiceGetSupportedCurrenciesResponseCaller {
-    private grpc:Caller caller;
+public isolated client class CurrencyServiceGetSupportedCurrenciesResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -823,8 +823,8 @@ public client class CurrencyServiceGetSupportedCurrenciesResponseCaller {
     }
 }
 
-public client class CurrencyServiceMoneyCaller {
-    private grpc:Caller caller;
+public isolated client class CurrencyServiceMoneyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -855,8 +855,8 @@ public client class CurrencyServiceMoneyCaller {
     }
 }
 
-public client class PaymentServiceChargeResponseCaller {
-    private grpc:Caller caller;
+public isolated client class PaymentServiceChargeResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -887,8 +887,8 @@ public client class PaymentServiceChargeResponseCaller {
     }
 }
 
-public client class EmailServiceEmptyCaller {
-    private grpc:Caller caller;
+public isolated client class EmailServiceEmptyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -919,8 +919,8 @@ public client class EmailServiceEmptyCaller {
     }
 }
 
-public client class CheckoutServicePlaceOrderResponseCaller {
-    private grpc:Caller caller;
+public isolated client class CheckoutServicePlaceOrderResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -951,8 +951,8 @@ public client class CheckoutServicePlaceOrderResponseCaller {
     }
 }
 
-public client class AdServiceAdResponseCaller {
-    private grpc:Caller caller;
+public isolated client class AdServiceAdResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/examples/online-boutique-microservice/recommendation-service/demo_pb.bal b/examples/online-boutique-microservice/recommendation-service/demo_pb.bal
index a17d95e06..202a3526f 100644
--- a/examples/online-boutique-microservice/recommendation-service/demo_pb.bal
+++ b/examples/online-boutique-microservice/recommendation-service/demo_pb.bal
@@ -535,8 +535,8 @@ public isolated client class AdServiceClient {
     }
 }
 
-public client class CartServiceEmptyCaller {
-    private grpc:Caller caller;
+public isolated client class CartServiceEmptyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -567,8 +567,8 @@ public client class CartServiceEmptyCaller {
     }
 }
 
-public client class CartServiceCartCaller {
-    private grpc:Caller caller;
+public isolated client class CartServiceCartCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -599,8 +599,8 @@ public client class CartServiceCartCaller {
     }
 }
 
-public client class RecommendationServiceListRecommendationsResponseCaller {
-    private grpc:Caller caller;
+public isolated client class RecommendationServiceListRecommendationsResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -631,8 +631,8 @@ public client class RecommendationServiceListRecommendationsResponseCaller {
     }
 }
 
-public client class ProductCatalogServiceListProductsResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ProductCatalogServiceListProductsResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -663,8 +663,8 @@ public client class ProductCatalogServiceListProductsResponseCaller {
     }
 }
 
-public client class ProductCatalogServiceSearchProductsResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ProductCatalogServiceSearchProductsResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -695,8 +695,8 @@ public client class ProductCatalogServiceSearchProductsResponseCaller {
     }
 }
 
-public client class ProductCatalogServiceProductCaller {
-    private grpc:Caller caller;
+public isolated client class ProductCatalogServiceProductCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -727,8 +727,8 @@ public client class ProductCatalogServiceProductCaller {
     }
 }
 
-public client class ShippingServiceGetQuoteResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ShippingServiceGetQuoteResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -759,8 +759,8 @@ public client class ShippingServiceGetQuoteResponseCaller {
     }
 }
 
-public client class ShippingServiceShipOrderResponseCaller {
-    private grpc:Caller caller;
+public isolated client class ShippingServiceShipOrderResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -791,8 +791,8 @@ public client class ShippingServiceShipOrderResponseCaller {
     }
 }
 
-public client class CurrencyServiceGetSupportedCurrenciesResponseCaller {
-    private grpc:Caller caller;
+public isolated client class CurrencyServiceGetSupportedCurrenciesResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -823,8 +823,8 @@ public client class CurrencyServiceGetSupportedCurrenciesResponseCaller {
     }
 }
 
-public client class CurrencyServiceMoneyCaller {
-    private grpc:Caller caller;
+public isolated client class CurrencyServiceMoneyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -855,8 +855,8 @@ public client class CurrencyServiceMoneyCaller {
     }
 }
 
-public client class PaymentServiceChargeResponseCaller {
-    private grpc:Caller caller;
+public isolated client class PaymentServiceChargeResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -887,8 +887,8 @@ public client class PaymentServiceChargeResponseCaller {
     }
 }
 
-public client class EmailServiceEmptyCaller {
-    private grpc:Caller caller;
+public isolated client class EmailServiceEmptyCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -919,8 +919,8 @@ public client class EmailServiceEmptyCaller {
     }
 }
 
-public client class CheckoutServicePlaceOrderResponseCaller {
-    private grpc:Caller caller;
+public isolated client class CheckoutServicePlaceOrderResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -951,8 +951,8 @@ public client class CheckoutServicePlaceOrderResponseCaller {
     }
 }
 
-public client class AdServiceAdResponseCaller {
-    private grpc:Caller caller;
+public isolated client class AdServiceAdResponseCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/examples/program-analyzer/client/program_analyzer_pb.bal b/examples/program-analyzer/client/program_analyzer_pb.bal
index 2c3744fb2..134107584 100644
--- a/examples/program-analyzer/client/program_analyzer_pb.bal
+++ b/examples/program-analyzer/client/program_analyzer_pb.bal
@@ -45,8 +45,8 @@ public isolated client class BalProgramAnalyzerClient {
     }
 }
 
-public client class BalProgramAnalyzerStringCaller {
-    private grpc:Caller caller;
+public isolated client class BalProgramAnalyzerStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/examples/program-analyzer/server/program_analyzer_pb.bal b/examples/program-analyzer/server/program_analyzer_pb.bal
index 2c3744fb2..134107584 100644
--- a/examples/program-analyzer/server/program_analyzer_pb.bal
+++ b/examples/program-analyzer/server/program_analyzer_pb.bal
@@ -45,8 +45,8 @@ public isolated client class BalProgramAnalyzerClient {
     }
 }
 
-public client class BalProgramAnalyzerStringCaller {
-    private grpc:Caller caller;
+public isolated client class BalProgramAnalyzerStringCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/examples/route-guide/client/route_guide_pb.bal b/examples/route-guide/client/route_guide_pb.bal
index 45074d0cf..c5d83fd84 100644
--- a/examples/route-guide/client/route_guide_pb.bal
+++ b/examples/route-guide/client/route_guide_pb.bal
@@ -79,8 +79,8 @@ public isolated client class RouteGuideClient {
     }
 }
 
-public client class RecordRouteStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RecordRouteStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -147,8 +147,8 @@ public class FeatureStream {
     }
 }
 
-public client class RouteChatStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RouteChatStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -191,8 +191,8 @@ public client class RouteChatStreamingClient {
     }
 }
 
-public client class RouteGuideRouteSummaryCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteSummaryCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -219,8 +219,8 @@ public client class RouteGuideRouteSummaryCaller {
     }
 }
 
-public client class RouteGuideRouteNoteCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteNoteCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -247,8 +247,8 @@ public client class RouteGuideRouteNoteCaller {
     }
 }
 
-public client class RouteGuideFeatureCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideFeatureCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/examples/route-guide/server/route_guide_pb.bal b/examples/route-guide/server/route_guide_pb.bal
index 45074d0cf..c5d83fd84 100644
--- a/examples/route-guide/server/route_guide_pb.bal
+++ b/examples/route-guide/server/route_guide_pb.bal
@@ -79,8 +79,8 @@ public isolated client class RouteGuideClient {
     }
 }
 
-public client class RecordRouteStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RecordRouteStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -147,8 +147,8 @@ public class FeatureStream {
     }
 }
 
-public client class RouteChatStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RouteChatStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -191,8 +191,8 @@ public client class RouteChatStreamingClient {
     }
 }
 
-public client class RouteGuideRouteSummaryCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteSummaryCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -219,8 +219,8 @@ public client class RouteGuideRouteSummaryCaller {
     }
 }
 
-public client class RouteGuideRouteNoteCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteNoteCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -247,8 +247,8 @@ public client class RouteGuideRouteNoteCaller {
     }
 }
 
-public client class RouteGuideFeatureCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideFeatureCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/integration-tests/modules/api/separate_module_pb.bal b/integration-tests/modules/api/separate_module_pb.bal
index 50fcd98ea..6b1e7d513 100644
--- a/integration-tests/modules/api/separate_module_pb.bal
+++ b/integration-tests/modules/api/separate_module_pb.bal
@@ -100,8 +100,8 @@ public isolated client class SeparateModuleServiceClient {
     }
 }
 
-public client class ClientStreamingStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class ClientStreamingStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -168,8 +168,8 @@ public class SMResStream {
     }
 }
 
-public client class Bidirectional1StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Bidirectional1StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -212,8 +212,8 @@ public client class Bidirectional1StreamingClient {
     }
 }
 
-public client class Bidirectional2StreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class Bidirectional2StreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -256,8 +256,8 @@ public client class Bidirectional2StreamingClient {
     }
 }
 
-public client class SeparateModuleServiceSMResCaller {
-    private grpc:Caller caller;
+public isolated client class SeparateModuleServiceSMResCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/load-tests/route_guide_bidirectional_streaming/src/route_guide_pb.bal b/load-tests/route_guide_bidirectional_streaming/src/route_guide_pb.bal
index 796de551e..474e415cc 100644
--- a/load-tests/route_guide_bidirectional_streaming/src/route_guide_pb.bal
+++ b/load-tests/route_guide_bidirectional_streaming/src/route_guide_pb.bal
@@ -79,8 +79,8 @@ public isolated client class RouteGuideClient {
     }
 }
 
-public client class RecordRouteStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RecordRouteStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -147,8 +147,8 @@ public class FeatureStream {
     }
 }
 
-public client class RouteChatStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RouteChatStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -191,8 +191,8 @@ public client class RouteChatStreamingClient {
     }
 }
 
-public client class RouteGuideRouteSummaryCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteSummaryCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -219,8 +219,8 @@ public client class RouteGuideRouteSummaryCaller {
     }
 }
 
-public client class RouteGuideRouteNoteCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteNoteCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -247,8 +247,8 @@ public client class RouteGuideRouteNoteCaller {
     }
 }
 
-public client class RouteGuideFeatureCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideFeatureCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/load-tests/route_guide_client_streaming/src/route_guide_pb.bal b/load-tests/route_guide_client_streaming/src/route_guide_pb.bal
index 796de551e..474e415cc 100644
--- a/load-tests/route_guide_client_streaming/src/route_guide_pb.bal
+++ b/load-tests/route_guide_client_streaming/src/route_guide_pb.bal
@@ -79,8 +79,8 @@ public isolated client class RouteGuideClient {
     }
 }
 
-public client class RecordRouteStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RecordRouteStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -147,8 +147,8 @@ public class FeatureStream {
     }
 }
 
-public client class RouteChatStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RouteChatStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -191,8 +191,8 @@ public client class RouteChatStreamingClient {
     }
 }
 
-public client class RouteGuideRouteSummaryCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteSummaryCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -219,8 +219,8 @@ public client class RouteGuideRouteSummaryCaller {
     }
 }
 
-public client class RouteGuideRouteNoteCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteNoteCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -247,8 +247,8 @@ public client class RouteGuideRouteNoteCaller {
     }
 }
 
-public client class RouteGuideFeatureCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideFeatureCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/load-tests/route_guide_server_streaming/src/route_guide_pb.bal b/load-tests/route_guide_server_streaming/src/route_guide_pb.bal
index 796de551e..474e415cc 100644
--- a/load-tests/route_guide_server_streaming/src/route_guide_pb.bal
+++ b/load-tests/route_guide_server_streaming/src/route_guide_pb.bal
@@ -79,8 +79,8 @@ public isolated client class RouteGuideClient {
     }
 }
 
-public client class RecordRouteStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RecordRouteStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -147,8 +147,8 @@ public class FeatureStream {
     }
 }
 
-public client class RouteChatStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RouteChatStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -191,8 +191,8 @@ public client class RouteChatStreamingClient {
     }
 }
 
-public client class RouteGuideRouteSummaryCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteSummaryCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -219,8 +219,8 @@ public client class RouteGuideRouteSummaryCaller {
     }
 }
 
-public client class RouteGuideRouteNoteCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteNoteCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -247,8 +247,8 @@ public client class RouteGuideRouteNoteCaller {
     }
 }
 
-public client class RouteGuideFeatureCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideFeatureCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
diff --git a/load-tests/route_guide_unary/src/route_guide_pb.bal b/load-tests/route_guide_unary/src/route_guide_pb.bal
index 796de551e..474e415cc 100644
--- a/load-tests/route_guide_unary/src/route_guide_pb.bal
+++ b/load-tests/route_guide_unary/src/route_guide_pb.bal
@@ -79,8 +79,8 @@ public isolated client class RouteGuideClient {
     }
 }
 
-public client class RecordRouteStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RecordRouteStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -147,8 +147,8 @@ public class FeatureStream {
     }
 }
 
-public client class RouteChatStreamingClient {
-    private grpc:StreamingClient sClient;
+public isolated client class RouteChatStreamingClient {
+    private final grpc:StreamingClient sClient;
 
     isolated function init(grpc:StreamingClient sClient) {
         self.sClient = sClient;
@@ -191,8 +191,8 @@ public client class RouteChatStreamingClient {
     }
 }
 
-public client class RouteGuideRouteSummaryCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteSummaryCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -219,8 +219,8 @@ public client class RouteGuideRouteSummaryCaller {
     }
 }
 
-public client class RouteGuideRouteNoteCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideRouteNoteCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;
@@ -247,8 +247,8 @@ public client class RouteGuideRouteNoteCaller {
     }
 }
 
-public client class RouteGuideFeatureCaller {
-    private grpc:Caller caller;
+public isolated client class RouteGuideFeatureCaller {
+    private final grpc:Caller caller;
 
     public isolated function init(grpc:Caller caller) {
         self.caller = caller;