diff --git a/compiler/cpp/src/generate/t_cpp_generator.cc b/compiler/cpp/src/generate/t_cpp_generator.cc
index 115dc89..4ee9d93 100644
--- a/compiler/cpp/src/generate/t_cpp_generator.cc
+++ b/compiler/cpp/src/generate/t_cpp_generator.cc
@@ -2102,7 +2102,7 @@
       indent() << "}" << endl;
     if (!gen_no_client_completion_) {
       f_header_ <<
-        indent() << "virtual void completed__(bool success) {}" << endl;
+        indent() << "virtual void completed__(bool /* success */) {}" << endl;
     }
   }