diff --git a/Contrib/ExDLL/exdll.h b/Contrib/ExDLL/exdll.h
index 1dd3f86b..d81070e5 100644
--- a/Contrib/ExDLL/exdll.h
+++ b/Contrib/ExDLL/exdll.h
@@ -1,6 +1,8 @@
 #ifndef _EXDLL_H_
 #define _EXDLL_H_
 
+#include <windows.h>
+
 // only include this file from one place in your DLL.
 // (it is all static, if you use it in two places it will fail)