diff --git a/include/llvm/Support/PredIteratorCache.h b/include/llvm/Support/PredIteratorCache.h
index 532d65e6d44..2de2a02461d 100644
--- a/include/llvm/Support/PredIteratorCache.h
+++ b/include/llvm/Support/PredIteratorCache.h
@@ -16,6 +16,9 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallVector.h"
 
+#ifndef LLVM_SUPPORT_PREDITERATORCACHE_H
+#define LLVM_SUPPORT_PREDITERATORCACHE_H
+
 namespace llvm {
 
   /// PredIteratorCache - This class is an extremely trivial cache for
@@ -55,3 +58,5 @@ namespace llvm {
   };
 } // end namespace llvm
 
+#endif
+