diff --git a/lib/CodeGen/MachineModuleInfo.cpp b/lib/CodeGen/MachineModuleInfo.cpp
index 3d3a995..149451b 100644
--- a/lib/CodeGen/MachineModuleInfo.cpp
+++ b/lib/CodeGen/MachineModuleInfo.cpp
@@ -1321,7 +1321,7 @@
 ///
 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;