diff --git a/src/proto/grpc/testing/test.proto b/src/proto/grpc/testing/test.proto
index 084d59f8aaf..801baf8b3b2 100644
--- a/src/proto/grpc/testing/test.proto
+++ b/src/proto/grpc/testing/test.proto
@@ -70,8 +70,9 @@ service TestService {
   rpc HalfDuplexCall(stream StreamingOutputCallRequest)
       returns (stream StreamingOutputCallResponse);
 
-  // A call that no server should implement
-  rpc UnimplementedCall(grpc.testing.Empty) returns (grpc.testing.Empty);
+  // The test server will not implement this method. It will be used
+  // to test the behavior when clients call unimplemented methods.
+  rpc UnimplementedMethod(grpc.testing.Empty) returns (grpc.testing.Empty);
 }
 
 // A simple service NOT implemented at servers so clients can test for
diff --git a/test/cpp/interop/interop_client.cc b/test/cpp/interop/interop_client.cc
index b43f166b96c..65519a03a88 100644
--- a/test/cpp/interop/interop_client.cc
+++ b/test/cpp/interop/interop_client.cc
@@ -944,15 +944,15 @@ bool InteropClient::DoUnimplementedMethod() {
   Empty response = Empty::default_instance();
   ClientContext context;
 
-  gpr_log(GPR_DEBUG, "here");
-
-  Status s = serviceStub_.Get()->UnimplementedCall(
+  Status s = serviceStub_.Get()->UnimplementedMethod(
     &context, request, &response);
 
   if (!AssertStatusCode(s, StatusCode::UNIMPLEMENTED)) {
     return false;
   }
 
+  GPR_ASSERT(s.error_message().empty());
+
   gpr_log(GPR_DEBUG, "unimplemented rpc done.");
   return true;
 }