diff --git a/llvm/lib/Support/SourceMgr.cpp b/llvm/lib/Support/SourceMgr.cpp
index b2f87d6..4cb9b2f 100644
--- a/llvm/lib/Support/SourceMgr.cpp
+++ b/llvm/lib/Support/SourceMgr.cpp
@@ -142,7 +142,7 @@
   // location to pull out the source line.
   SmallVector<std::pair<unsigned, unsigned>, 4> ColRanges;
   std::pair<unsigned, unsigned> LineAndCol;
-  const char *BufferID = "<unknown>";
+  StringRef BufferID = "<unknown>";
   std::string LineStr;
   
   if (Loc.isValid()) {