diff --git a/icbd.c b/icbd.c
index 3b35490..c43ffb4 100644
--- a/icbd.c
+++ b/icbd.c
@@ -59,10 +59,6 @@ void icbd_grplist(char *);
 void icbd_restrict(void);
 void icbd_write(struct icb_session *, char *, ssize_t);
 
-/* event.h as it's shipped with OpenBSD doesn't include this prototype */
-void bufferevent_setwatermark(struct bufferevent *, short events,
-    size_t lowmark, size_t highmark);
-
 int
 main(int argc, char *argv[])
 {