diff --git a/src/compiler/cpp_generator.cc b/src/compiler/cpp_generator.cc
index d3d6224de2942982ae8052c73e88a0c6487b3ef3..97295bed4518b9325d8d420f2045c4b93baa14f0 100644
--- a/src/compiler/cpp_generator.cc
+++ b/src/compiler/cpp_generator.cc
@@ -1106,6 +1106,7 @@ void PrintSourceService(grpc::protobuf::io::Printer *printer,
 
   printer->Print(*vars, "$ns$$Service$::Service::Service() {\n");
   printer->Indent();
+  printer->Print(*vars, "(void)$prefix$$Service$_method_names;\n");
   for (int i = 0; i < service->method_count(); ++i) {
     const grpc::protobuf::MethodDescriptor *method = service->method(i);
     (*vars)["Idx"] = as_string(i);