diff --git a/lib/cpp/src/Thrift.h b/lib/cpp/src/Thrift.h
index e497255..347ec21 100644
--- a/lib/cpp/src/Thrift.h
+++ b/lib/cpp/src/Thrift.h
@@ -23,7 +23,7 @@
 
   ~TException() throw() {}
 
-  const char* what() {
+  const char* what() const throw() {
     if (message_.empty()) {
       return "Default TException.";
     } else {