diff --git a/sbin/ifconfig/ifconfig.c b/sbin/ifconfig/ifconfig.c
--- a/sbin/ifconfig/ifconfig.c
+++ b/sbin/ifconfig/ifconfig.c
@@ -585,7 +585,7 @@
 
 #ifdef JAIL
 	if (args.jail_name) {
-		jid = jail_getid(optarg);
+		jid = jail_getid(args.jail_name);
 		if (jid == -1)
 			Perror("jail not found");
 		if (jail_attach(jid) != 0)