diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 532425d..309284e 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -539,6 +539,13 @@ done:
 	case IPV6_MULTICAST_IF:
 		if (sk->sk_type == SOCK_STREAM)
 			goto e_inval;
+
+		if (val == 0) {
+			np->mcast_oif = 0;
+			retv = 0;
+			break;
+		}
+
 		if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != val)
 			goto e_inval;