diff --git a/net/ipv4/netfilter/ip_conntrack_netlink.c b/net/ipv4/netfilter/ip_conntrack_netlink.c
index d1dde1417ef7d049175473648d84a667fee837cc..cfc5487e627acf7d6d76e3108ee9f46721d8d5a2 100644
--- a/net/ipv4/netfilter/ip_conntrack_netlink.c
+++ b/net/ipv4/netfilter/ip_conntrack_netlink.c
@@ -593,7 +593,7 @@ static int ctnetlink_parse_nat_proto(struct nfattr *attr,
 	nfattr_parse_nested(tb, CTA_PROTONAT_MAX, attr);
 
 	if (nfattr_bad_size(tb, CTA_PROTONAT_MAX, cta_min_protonat))
-		return -1;
+		return -EINVAL;
 
 	npt = ip_nat_proto_find_get(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum);
 	if (!npt)