diff --git a/windows/winproc.c b/windows/winproc.c
index 74635b11e77757dd7096011842ce508172336b42..00224a3801727e1e1b66f61cc854a79918e0e538 100644
--- a/windows/winproc.c
+++ b/windows/winproc.c
@@ -6,6 +6,8 @@
  */
 
 #include <string.h>
+
+#include "config.h"
 #include "windef.h"
 #include "winnls.h"
 #include "wingdi.h"