diff --git a/iptables/nft-arp.c b/iptables/nft-arp.c
index 1af7202..3af1b4b 100644
--- a/iptables/nft-arp.c
+++ b/iptables/nft-arp.c
@@ -345,7 +345,7 @@
 			fw->arp.invflags |= ARPT_INV_ARPOP;
 		break;
 	default:
-		if (!fw->arp.arhln)
+		if (fw->arp.arhln < 0)
 			break;
 
 		if (offset == sizeof(struct arphdr) + fw->arp.arhln) {