diff --git a/src/keyboard.h b/src/keyboard.h
index 5c631782890..9ba115618da 100644
--- a/src/keyboard.h
+++ b/src/keyboard.h
@@ -340,3 +340,4 @@ extern int gen_help_event P_ ((struct input_event *, Lisp_Object,
 			       Lisp_Object, Lisp_Object, Lisp_Object, int));
 extern void kbd_buffer_store_help_event P_ ((Lisp_Object, Lisp_Object));
 extern Lisp_Object menu_item_eval_property P_ ((Lisp_Object));
+extern int  kbd_buffer_events_waiting P_ ((int));