diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index 9eb9285..b071543 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -354,8 +354,15 @@
 				    (x->ealg->alg_key_len + 7) / 8))
 		goto error;
 	x->props.header_len = sizeof(struct ip_esp_hdr) + esp->conf.ivlen;
-	if (x->props.mode == XFRM_MODE_TUNNEL)
+	switch (x->props.mode) {
+	case XFRM_MODE_BEET:
+	case XFRM_MODE_TRANSPORT:
+		break;
+	case XFRM_MODE_TUNNEL:
 		x->props.header_len += sizeof(struct ipv6hdr);
+	default:
+		goto error;
+	}
 	x->data = esp;
 	return 0;