diff --git a/include/osmocom/core/timer.h b/include/osmocom/core/timer.h
index dbda13f..48e7d8d 100644
--- a/include/osmocom/core/timer.h
+++ b/include/osmocom/core/timer.h
@@ -65,6 +65,8 @@
  * timer management
  */
 
+void osmo_timer_setup(struct osmo_timer_list *timer, void (*cb)(void *data), void *data);
+
 void osmo_timer_add(struct osmo_timer_list *timer);
 
 void osmo_timer_schedule(struct osmo_timer_list *timer, int seconds, int microseconds);