diff --git a/_imagingcms.c b/_imagingcms.c
index b2903adbf..99da647ae 100644
--- a/_imagingcms.c
+++ b/_imagingcms.c
@@ -29,6 +29,7 @@ http://www.cazabon.com\n\
 #include "py3.h"
 
 #ifdef WIN32
+#include <windows.h>
 #include <windef.h>
 #include <wingdi.h>
 #endif