diff --git a/lib/Lex/TokenLexer.cpp b/lib/Lex/TokenLexer.cpp
index 5560949..49dc016 100644
--- a/lib/Lex/TokenLexer.cpp
+++ b/lib/Lex/TokenLexer.cpp
@@ -492,7 +492,7 @@
           PP.Diag(Loc,
                   PP.getLangOptions().Microsoft ? diag::err_pp_bad_paste_ms 
                                                 : diag::err_pp_bad_paste)
-            << std::string(Buffer.begin(), Buffer.end());
+            << Buffer.str();
         }
 
         // Do not consume the RHS.