diff --git a/bufferevent-internal.h b/bufferevent-internal.h
index f85f376e..134bb337 100644
--- a/bufferevent-internal.h
+++ b/bufferevent-internal.h
@@ -358,7 +358,6 @@ static inline void bufferevent_trigger_nolock_(struct bufferevent *bufev, short
 
 /* Making this inline since all of the common-case calls to this function in
  * libevent use constant arguments. */
-size_t evbuffer_get_length(const struct evbuffer *buf);
 static inline void
 bufferevent_trigger_nolock_(struct bufferevent *bufev, short iotype, int options)
 {