diff --git a/include/llvm/Support/Mangler.h b/include/llvm/Support/Mangler.h
index 9b885d05497..3fe88c1126a 100644
--- a/include/llvm/Support/Mangler.h
+++ b/include/llvm/Support/Mangler.h
@@ -19,7 +19,7 @@
 #include <string>
 
 namespace llvm {
-class StringRef;
+class Twine;
 class Type;
 class Module;
 class Value;
@@ -112,7 +112,7 @@ public:
   /// does this for you, so there's no point calling it on the result
   /// from getValueName.
   ///
-  std::string makeNameProper(StringRef x,
+  std::string makeNameProper(const Twine &Name,
                              ManglerPrefixTy PrefixTy = Mangler::Default);
   
   /// getNameWithPrefix - Fill OutName with the name of the appropriate prefix
diff --git a/lib/VMCore/Mangler.cpp b/lib/VMCore/Mangler.cpp
index 2f546b11e46..5783ddfba94 100644
--- a/lib/VMCore/Mangler.cpp
+++ b/lib/VMCore/Mangler.cpp
@@ -16,7 +16,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringMap.h"
-#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/SmallString.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
 
@@ -32,8 +32,11 @@ static std::string MangleLetter(unsigned char C) {
 /// makeNameProper - We don't want identifier names non-C-identifier characters
 /// in them, so mangle them as appropriate.
 ///
-std::string Mangler::makeNameProper(StringRef X,
+std::string Mangler::makeNameProper(const Twine &TheName,
                                     ManglerPrefixTy PrefixTy) {
+  SmallString<256> TmpData;
+  TheName.toVector(TmpData);
+  StringRef X = TmpData.str();
   assert(!X.empty() && "Cannot mangle empty strings");
   
   if (!UseQuotes) {