diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 9ccfef3..77aecbe 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -481,7 +481,7 @@
 
 	pref = rinfo->route_pref;
 	if (pref == ICMPV6_ROUTER_PREF_INVALID)
-		pref = ICMPV6_ROUTER_PREF_MEDIUM;
+		return -EINVAL;
 
 	lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);