diff --git a/lib/Basic/IdentifierTable.cpp b/lib/Basic/IdentifierTable.cpp
index 4711faa..109761c 100644
--- a/lib/Basic/IdentifierTable.cpp
+++ b/lib/Basic/IdentifierTable.cpp
@@ -17,6 +17,7 @@
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstdio>
 
@@ -92,7 +93,8 @@
     KEYBORLAND = 0x100,
     KEYOPENCL = 0x200,
     KEYC1X = 0x400,
-    KEYALL = 0x7ff
+    KEYARC = 0x800,
+    KEYALL = 0x0fff
   };
 }
 
@@ -120,7 +122,8 @@
   else if (LangOpts.OpenCL && (Flags & KEYOPENCL)) AddResult = 2;
   else if (!LangOpts.CPlusPlus && (Flags & KEYNOCXX)) AddResult = 2;
   else if (LangOpts.C1X && (Flags & KEYC1X)) AddResult = 2;
-
+  else if (LangOpts.ObjCAutoRefCount && (Flags & KEYARC)) AddResult = 2;
+           
   // Don't add this keyword if disabled in this language.
   if (AddResult == 0) return;