diff --git a/src/proto/gui_w32.pro b/src/proto/gui_w32.pro
index e35373c..20a92b9 100644
--- a/src/proto/gui_w32.pro
+++ b/src/proto/gui_w32.pro
@@ -2,6 +2,7 @@
 int directx_enabled(void);
 int gui_mch_set_rendering_options(char_u *s);
 int gui_mch_is_blinking(void);
+int gui_mch_is_blink_off(void);
 void gui_mch_set_blinking(long wait, long on, long off);
 void gui_mch_stop_blink(void);
 void gui_mch_start_blink(void);