diff --git a/sys/net/if.c b/sys/net/if.c
index cb1686117d2..da323cc19a3 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1728,7 +1728,7 @@ ifaof_ifpforaddr(struct sockaddr *addr, struct ifnet *ifp)
 	u_int af = addr->sa_family;
 
 	if (af >= AF_MAX)
-		return (0);
+		return (NULL);
 	IF_ADDR_LOCK(ifp);
 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 		if (ifa->ifa_addr->sa_family != af)