diff --git a/llvm/lib/Support/Atomic.cpp b/llvm/lib/Support/Atomic.cpp
index 9559ad729570..2ef32b08ef28 100644
--- a/llvm/lib/Support/Atomic.cpp
+++ b/llvm/lib/Support/Atomic.cpp
@@ -17,6 +17,7 @@
 using namespace llvm;
 
 #if defined(_MSC_VER)
+#include <Intrin.h>
 #include <windows.h>
 #undef MemoryFence
 #endif