diff --git a/include/llvm/CodeGen/MachineModuleInfo.h b/include/llvm/CodeGen/MachineModuleInfo.h
index a9567d2e255..9d98776f548 100644
--- a/include/llvm/CodeGen/MachineModuleInfo.h
+++ b/include/llvm/CodeGen/MachineModuleInfo.h
@@ -37,6 +37,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/UniqueVector.h"
 #include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/StringMap.h"
 #include "llvm/GlobalValue.h"
 #include "llvm/Pass.h"
 
@@ -777,7 +778,7 @@ class DISerializer {
   DenseMap<DebugInfoDesc *, GlobalVariable *> DescGlobals;
 
   // Previously defined strings.
-  DenseMap<const char *, Constant*> StringCache;
+  StringMap<Constant*> StringCache;
 public:
   DISerializer()
     : M(NULL), StrPtrTy(NULL), EmptyStructPtrTy(NULL), TagTypes(),
diff --git a/lib/CodeGen/MachineModuleInfo.cpp b/lib/CodeGen/MachineModuleInfo.cpp
index 3d3a9957bb0..149451b8301 100644
--- a/lib/CodeGen/MachineModuleInfo.cpp
+++ b/lib/CodeGen/MachineModuleInfo.cpp
@@ -1321,7 +1321,7 @@ const StructType *DISerializer::getTagType(DebugInfoDesc *DD) {
 ///
 Constant *DISerializer::getString(const std::string &String) {
   // Check string cache for previous edition.
-  Constant *&Slot = StringCache[String.c_str()];
+  Constant *&Slot = StringCache[String];
 
   // Return Constant if previously defined.
   if (Slot) return Slot;