diff --git a/src/ruby/bin/interop/test/cpp/interop/messages.rb b/src/ruby/bin/interop/test/cpp/interop/messages.rb
index 491608bff26..b86cd396a9f 100644
--- a/src/ruby/bin/interop/test/cpp/interop/messages.rb
+++ b/src/ruby/bin/interop/test/cpp/interop/messages.rb
@@ -41,10 +41,13 @@ Google::Protobuf::DescriptorPool.generated_pool.build do
     optional :response_type, :enum, 1, "grpc.testing.PayloadType"
     optional :response_size, :int32, 2
     optional :payload, :message, 3, "grpc.testing.Payload"
+    optional :fill_username, :bool, 4
+    optional :fill_oauth_scope, :bool, 5
   end
   add_message "grpc.testing.SimpleResponse" do
     optional :payload, :message, 1, "grpc.testing.Payload"
-    optional :effective_gaia_user_id, :int64, 2
+    optional :username, :string, 2
+    optional :oauth_scope, :string, 3
   end
   add_message "grpc.testing.StreamingInputCallRequest" do
     optional :payload, :message, 1, "grpc.testing.Payload"