diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 15c3774..9e305d74 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1335,7 +1335,7 @@
 	skb->ip_summed = CHECKSUM_NONE;
 
 	/* Check if there is enough headroom to insert fragment header. */
-	if ((skb_headroom(skb) < frag_hdr_sz) &&
+	if ((skb_mac_header(skb) < skb->head + frag_hdr_sz) &&
 	    pskb_expand_head(skb, frag_hdr_sz, 0, GFP_ATOMIC))
 		goto out;