diff --git a/src/proto/time.pro b/src/proto/time.pro
index affdb7a..7e44bca 100644
--- a/src/proto/time.pro
+++ b/src/proto/time.pro
@@ -13,6 +13,7 @@
 long check_due_timer(void);
 void stop_timer(timer_T *timer);
 int set_ref_in_timer(int copyID);
+int timer_valid(timer_T *timer);
 void timer_free_all(void);
 void f_timer_info(typval_T *argvars, typval_T *rettv);
 void f_timer_pause(typval_T *argvars, typval_T *rettv);