diff --git a/include/event2/bufferevent.h b/include/event2/bufferevent.h
index 2b8bb6f6..5ca707fa 100644
--- a/include/event2/bufferevent.h
+++ b/include/event2/bufferevent.h
@@ -573,6 +573,7 @@ struct bufferevent_rate_limit_group *bufferevent_rate_limit_group_new(
 	struct event_base *base,
 	const struct ev_token_bucket_cfg *cfg);
 /*XXX we need a bufferevent_rate_limit_group_set_cfg */
+/*XXX we need a bufferevent_rate_limit_group_free */
 
 /**
    Add 'bev' to the list of bufferevents whose aggregate reading and writing