diff --git a/src/proto/gui_x11.pro b/src/proto/gui_x11.pro
index 2d2eafa..ccaf99f 100644
--- a/src/proto/gui_x11.pro
+++ b/src/proto/gui_x11.pro
@@ -54,6 +54,7 @@
 void gui_mch_draw_menubar(void);
 void gui_x11_menu_cb(Widget w, XtPointer client_data, XtPointer call_data);
 int gui_mch_is_blinking(void);
+int gui_mch_is_blink_off(void);
 void gui_mch_set_blinking(long waittime, long on, long off);
 void gui_mch_stop_blink(void);
 void gui_mch_start_blink(void);