--- src/sys/platform/vkernel/platform/init.c	2008/05/27 05:25:35	1.55
+++ src/sys/platform/vkernel/platform/init.c	2008/05/27 07:48:00	1.56
@@ -1114,7 +1114,9 @@ netif_init_tap(int tap_unit, in_addr_t *
 	}
 
 back:
-	if (ifbridge == NULL) {
+	if (tap_unit < 0) {
+		/* Do nothing */
+	} else if (ifbridge == NULL) {
 		/* Set tap(4) address/netmask */
 		if (netif_set_tapaddr(tap_unit, tap_addr, netmask, s) < 0)
 			return -1;