diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index ce794d6acb70..9a3697172d5e 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -458,6 +458,8 @@ done:
 	case IPV6_MULTICAST_LOOP:
 		if (optlen < sizeof(int))
 			goto e_inval;
+		if (val != valbool)
+			goto e_inval;
 		np->mc_loop = valbool;
 		retv = 0;
 		break;