diff --git a/net/ipv4/ipcomp.c b/net/ipv4/ipcomp.c
index 6290675..c857f6f 100644
--- a/net/ipv4/ipcomp.c
+++ b/net/ipv4/ipcomp.c
@@ -27,7 +27,7 @@
 {
 	struct net *net = dev_net(skb->dev);
 	__be32 spi;
-	struct iphdr *iph = (struct iphdr *)skb->data;
+	const struct iphdr *iph = (const struct iphdr *)skb->data;
 	struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
 	struct xfrm_state *x;
 
@@ -36,7 +36,7 @@
 		return;
 
 	spi = htonl(ntohs(ipch->cpi));
-	x = xfrm_state_lookup(net, skb->mark, (xfrm_address_t *)&iph->daddr,
+	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
 			      spi, IPPROTO_COMP, AF_INET);
 	if (!x)
 		return;