diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index ac13a6a..ff56086 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -313,7 +313,7 @@
 		goto out;
 
 	/* create a copy of the skb, if needed, to modify it. */
-	if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
+	if (skb_cow(skb, ETH_HLEN) < 0)
 		goto out;
 
 	icmp_packet = (struct icmp_packet_rr *)skb->data;
@@ -368,7 +368,7 @@
 		goto out;
 
 	/* create a copy of the skb, if needed, to modify it. */
-	if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
+	if (skb_cow(skb, ETH_HLEN) < 0)
 		goto out;
 
 	icmp_packet = (struct icmp_packet *)skb->data;
@@ -454,7 +454,7 @@
 		goto out;
 
 	/* create a copy of the skb, if needed, to modify it. */
-	if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
+	if (skb_cow(skb, ETH_HLEN) < 0)
 		goto out;
 
 	icmp_packet = (struct icmp_packet_rr *)skb->data;
@@ -841,7 +841,7 @@
 		goto out;
 
 	/* create a copy of the skb, if needed, to modify it. */
-	if (skb_cow(skb, sizeof(struct ethhdr)) < 0)
+	if (skb_cow(skb, ETH_HLEN) < 0)
 		goto out;
 
 	unicast_packet = (struct unicast_packet *)skb->data;