diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index c90e75a..f84041d 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -459,10 +459,7 @@
 	if (rarp->ar_pro != htons(ETH_P_IP))
 		goto drop;
 
-	if (!pskb_may_pull(skb,
-			   sizeof(struct arphdr) +
-			   (2 * dev->addr_len) +
-			   (2 * 4)))
+	if (!pskb_may_pull(skb, arp_hdr_len(dev)))
 		goto drop;
 
 	/* OK, it is all there and looks valid, process... */