diff --git a/res/res_pjsip_pubsub.c b/res/res_pjsip_pubsub.c
index 530a3b81bc..fc4a940515 100644
--- a/res/res_pjsip_pubsub.c
+++ b/res/res_pjsip_pubsub.c
@@ -1988,6 +1988,7 @@ static int serialized_send_notify(void *userdata)
 	}
 
 	send_notify(sub_tree, 0);
+	sub_tree->notify_sched_id = -1;
 	ao2_cleanup(sub_tree);
 	return 0;
 }