diff --git a/tools/widl/utils.c b/tools/widl/utils.c
index 379a36d..ff2fba9 100644
--- a/tools/widl/utils.c
+++ b/tools/widl/utils.c
@@ -20,6 +20,7 @@
  */
 
 #include "config.h"
+#include "wine/port.h"
 
 #include <assert.h>
 #include <stdio.h>