diff --git a/windows/sysmetrics.c b/windows/sysmetrics.c
index b2b832c..6d52ada 100644
--- a/windows/sysmetrics.c
+++ b/windows/sysmetrics.c
@@ -6,6 +6,8 @@
  */
 
 #include <stdio.h>
+
+#include "wine/winuser16.h"
 #include "winbase.h"
 #include "winuser.h"
 #include "monitor.h"