diff --git a/clang/include/clang/Basic/Diagnostic.h b/clang/include/clang/Basic/Diagnostic.h
index 201313cbb6b65139bb8f61f5313ad0059bea94cb..85680792afcf5dfa93be025c178fac167bd2ca11 100644
--- a/clang/include/clang/Basic/Diagnostic.h
+++ b/clang/include/clang/Basic/Diagnostic.h
@@ -119,7 +119,7 @@ public:
   /// Report - Issue the message to the client.  DiagID is a member of the
   /// diag::kind enum.  
   void Report(SourceLocation Pos, unsigned DiagID,
-              const std::string &Extra = "");
+              const std::string &Extra = std::string());
 };
 
 /// DiagnosticClient - This is an abstract interface implemented by clients of