diff --git a/net/ipv4/ah4.c b/net/ipv4/ah4.c
index 7a23e59c374a3491c802e83f45638c82e6b2a64a..39f6211f1496050957ba6082d36a01799822c21b 100644
--- a/net/ipv4/ah4.c
+++ b/net/ipv4/ah4.c
@@ -46,7 +46,7 @@ static int ip_clear_mutable_options(struct iphdr *iph, __be32 *daddr)
 			memcpy(daddr, optptr+optlen-4, 4);
 			/* Fall through */
 		default:
-			memset(optptr+2, 0, optlen-2);
+			memset(optptr, 0, optlen);
 		}
 		l -= optlen;
 		optptr += optlen;