diff --git a/lib/rbs/namespace.rb b/lib/rbs/namespace.rb
index 67b2ef3f9..e8f20bd7c 100644
--- a/lib/rbs/namespace.rb
+++ b/lib/rbs/namespace.rb
@@ -119,6 +119,7 @@ def ascend
 
 module Kernel
   def Namespace(name)
+    warn "Kernel#Namespace() is deprecated. Use RBS::Namespace.parse instead.", category: :deprecated
     RBS::Namespace.parse(name)
   end
 end
diff --git a/sig/namespace.rbs b/sig/namespace.rbs
index 3ab23affd..cbb329468 100644
--- a/sig/namespace.rbs
+++ b/sig/namespace.rbs
@@ -141,7 +141,6 @@ module RBS
 end
 
 module Kernel
-  # Parses given string and returns Namespace.
-  #
-  def Namespace: (String) -> RBS::Namespace
+  # Deprecated: Use `RBS::Namespace.parse` instead
+  %a{steep:deprecated} def Namespace: (String) -> RBS::Namespace
 end
diff --git a/test/rbs/signature_parsing_test.rb b/test/rbs/signature_parsing_test.rb
index 95e40805c..172188834 100644
--- a/test/rbs/signature_parsing_test.rb
+++ b/test/rbs/signature_parsing_test.rb
@@ -2153,7 +2153,7 @@ class Foo
         end
 
         use.clauses[1].tap do |clause|
-          assert_equal Namespace("RBS::AST::Declarations::"), clause.namespace
+          assert_equal RBS::Namespace.parse("RBS::AST::Declarations::"), clause.namespace
           assert_equal "RBS::AST::Declarations::", clause.location[:namespace].source
           assert_equal "*", clause.location[:star].source
         end
diff --git a/test/rbs/use_map_test.rb b/test/rbs/use_map_test.rb
index 7113a2ddb..32f8bfad5 100644
--- a/test/rbs/use_map_test.rb
+++ b/test/rbs/use_map_test.rb
@@ -36,7 +36,7 @@ def test_import_single_clause
   end
 
   def test_import_wildcard_clause
-    map.build_map(Use::WildcardClause.new(namespace: Namespace("Foo::"), location: nil))
+    map.build_map(Use::WildcardClause.new(namespace: RBS::Namespace.parse("Foo::"), location: nil))
 
     assert_equal TypeName("::Foo::M"), map.resolve?(TypeName("M"))
     assert_equal TypeName("::Foo::_I"), map.resolve?(TypeName("_I"))