diff --git a/llvm/include/llvm/ADT/BitVector.h b/llvm/include/llvm/ADT/BitVector.h
index d26cd80460f6..5284be8c4a02 100644
--- a/llvm/include/llvm/ADT/BitVector.h
+++ b/llvm/include/llvm/ADT/BitVector.h
@@ -71,7 +71,7 @@ public:
 };
 
 class BitVector {
-  typedef unsigned long BitWord;
+  typedef uintptr_t BitWord;
 
   enum { BITWORD_SIZE = (unsigned)sizeof(BitWord) * CHAR_BIT };