1 files changed, 2 insertions, 1 deletions
diff --git a/lib/Support/Regex.cpp b/lib/Support/Regex.cpp
index d3e29ac..e8344ef 100644
--- a/lib/Support/Regex.cpp
+++ b/lib/Support/Regex.cpp
@@ -15,6 +15,7 @@
 #include "regex_impl.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
 #include <string>
 using namespace llvm;
 
@@ -158,7 +159,7 @@ std::string Regex::sub(StringRef Repl, StringRef String,
           RefValue < Matches.size())
         Res += Matches[RefValue];
       else if (Error && Error->empty())
-        *Error = "invalid backreference string '" + Ref.str() + "'";
+        *Error = ("invalid backreference string '" + Twine(Ref) + "'").str();
       break;
     }
     }