diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 5cd5bbe..8c2b2b0 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -515,7 +515,7 @@
 	struct net_device *tdev;			/* Device to other host */
 	struct iphdr  *old_iph = ip_hdr(skb);
 	struct iphdr  *iph;			/* Our new IP header */
-	int    max_headroom;			/* The extra header space needed */
+	unsigned int max_headroom;		/* The extra header space needed */
 	__be32 dst = tiph->daddr;
 	int    mtu;