diff --git a/net/netfilter/xt_nat.c b/net/netfilter/xt_nat.c
index b4f7bbc3f3ca..51c7f7ce88d9 100644
--- a/net/netfilter/xt_nat.c
+++ b/net/netfilter/xt_nat.c
@@ -26,6 +26,15 @@ static int xt_nat_checkentry_v0(const struct xt_tgchk_param *par)
 
 static int xt_nat_checkentry(const struct xt_tgchk_param *par)
 {
+	switch (par->family) {
+	case NFPROTO_IPV4:
+	case NFPROTO_IPV6:
+	case NFPROTO_INET:
+		break;
+	default:
+		return -EINVAL;
+	}
+
 	return nf_ct_netns_get(par->net, par->family);
 }