diff --git a/openbsd/sys/netinet/in.h b/openbsd/sys/netinet/in.h
index f6e0d9cbd5..a70c0ba846 100644
--- a/openbsd/sys/netinet/in.h
+++ b/openbsd/sys/netinet/in.h
@@ -586,7 +586,7 @@ struct in6_pktinfo {
 __BEGIN_DECLS
 int	   bindresvport __P((int, struct sockaddr_in *));
 struct sockaddr;
-int	   bindresvport_sa __P((int, struct sockaddr *, int));
+int	   bindresvport_sa __P((int, struct sockaddr *));
 __END_DECLS
 
 #else