diff --git a/openapi-core/src/main/java/io/ballerina/openapi/core/generators/client/AbstractFunctionSignatureGenerator.java b/openapi-core/src/main/java/io/ballerina/openapi/core/generators/client/AbstractFunctionSignatureGenerator.java
index 016e216dd..becc6d453 100644
--- a/openapi-core/src/main/java/io/ballerina/openapi/core/generators/client/AbstractFunctionSignatureGenerator.java
+++ b/openapi-core/src/main/java/io/ballerina/openapi/core/generators/client/AbstractFunctionSignatureGenerator.java
@@ -93,9 +93,6 @@ public Optional<FunctionSignatureNode> generateFunctionSignature() {
         FunctionReturnTypeGeneratorImp functionReturnType = getFunctionReturnTypeGenerator();
         Optional<ReturnTypeDescriptorNode> returnType = functionReturnType.getReturnType();
         diagnostics.addAll(functionReturnType.getDiagnostics());
-        if (returnType.isEmpty()) {
-            return Optional.empty();
-        }
 
         //create function signature node
         return returnType.map(returnTypeDescriptorNode -> NodeFactory.createFunctionSignatureNode(