diff --git a/src/Phpro/SoapClient/CodeGenerator/Assembler/ExtendingTypeAssembler.php b/src/Phpro/SoapClient/CodeGenerator/Assembler/ExtendingTypeAssembler.php
index df1edf6b..d3c8fbd3 100644
--- a/src/Phpro/SoapClient/CodeGenerator/Assembler/ExtendingTypeAssembler.php
+++ b/src/Phpro/SoapClient/CodeGenerator/Assembler/ExtendingTypeAssembler.php
@@ -39,7 +39,7 @@ public function assemble(ContextInterface $context)
 
         $namespace = $type->getNamespace();
         $typeName = Normalizer::normalizeClassname($extending['type']);
-        $extendedClassName = sprintf('\\%s\\%s', $namespace, $typeName);
+        $extendedClassName = sprintf('%s\\%s', $namespace, $typeName);
 
         try {
             $extendAssembler = new ExtendAssembler($extendedClassName);
diff --git a/test/PhproTest/SoapClient/Unit/CodeGenerator/Assembler/ExtendingTypeAssemblerTest.php b/test/PhproTest/SoapClient/Unit/CodeGenerator/Assembler/ExtendingTypeAssemblerTest.php
index eaf610d7..fef4d08c 100644
--- a/test/PhproTest/SoapClient/Unit/CodeGenerator/Assembler/ExtendingTypeAssemblerTest.php
+++ b/test/PhproTest/SoapClient/Unit/CodeGenerator/Assembler/ExtendingTypeAssemblerTest.php
@@ -41,7 +41,7 @@ function it_can_assemble_type_context()
     /**
      * @test
      */
-    function it_assembles_a_type()
+    function it_assembles_a_type_in_same_namespace()
     {
         $assembler = new ExtendingTypeAssembler();
         $context = $this->createContext();
@@ -51,7 +51,29 @@ function it_assembles_a_type()
         $expected = <<<CODE
 namespace MyNamespace;
 
-use \MyNamespace\MyBaseType;
+class MyType extends MyBaseType
+{
+}
+
+CODE;
+
+        $this->assertEquals($expected, $code);
+    }
+
+    /**
+     * @test
+     */
+    function it_assembles_a_type_in_other_namespace()
+    {
+        $assembler = new ExtendingTypeAssembler();
+        $context = $this->createContext('OtherNamespace');
+        $assembler->assemble($context);
+
+        $code = $context->getClass()->generate();
+        $expected = <<<CODE
+namespace MyNamespace;
+
+use OtherNamespace\MyBaseType;
 
 class MyType extends MyBaseType
 {
@@ -119,10 +141,10 @@ class MyType
     /**
      * @return TypeContext
      */
-    private function createContext()
+    private function createContext(?string $importedNamespace = null)
     {
         $class = new ClassGenerator('MyType', 'MyNamespace');
-        $type = new Type('MyNamespace', 'MyType', [], XsdType::create('MyType')->withMeta(static fn (TypeMeta $meta) => $meta->withExtends([
+        $type = new Type($importedNamespace ?? 'MyNamespace', 'MyType', [], XsdType::create('MyType')->withMeta(static fn (TypeMeta $meta) => $meta->withExtends([
             'type' => 'MyBaseType',
             'namespace' => 'xxxx'
         ])));