diff --git a/lib/Support/Windows/Windows.h b/lib/Support/Windows/Windows.h
index 2ddd15efa19..4cdac788a0e 100644
--- a/lib/Support/Windows/Windows.h
+++ b/lib/Support/Windows/Windows.h
@@ -25,6 +25,7 @@
 #define WIN32_LEAN_AND_MEAN
 
 #include "llvm/Config/config.h" // Get build system configuration settings
+#include "llvm/Support/Compiler.h"
 #include <windows.h>
 #include <wincrypt.h>
 #include <shlobj.h>