diff --git a/sys/net/if_sl.c b/sys/net/if_sl.c
index db469053e40a..346bd91098dd 100644
--- a/sys/net/if_sl.c
+++ b/sys/net/if_sl.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)if_sl.c	8.6 (Berkeley) 2/1/94
- * $Id: if_sl.c,v 1.22 1995/06/21 09:11:22 davidg Exp $
+ * $Id: if_sl.c,v 1.23 1995/06/21 10:13:23 davidg Exp $
  */
 
 /*
@@ -909,6 +909,9 @@ slioctl(ifp, cmd, data)
 	switch (cmd) {
 
 	case SIOCSIFADDR:
+		if (ifa->ifa_addr->sa_family == AF_INET)
+			ifp->if_flags |= IFF_UP;
+		/* FALLTHROUGH */
 	case SIOCSIFDSTADDR:
 		if (ifa->ifa_addr->sa_family != AF_INET)
 			error = EAFNOSUPPORT;