diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index 44d1ea3..655170f 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -830,12 +830,16 @@ static int tcp_packet(struct nf_conn *ct,
 	th = skb_header_pointer(skb, dataoff, sizeof(_tcph), &_tcph);
 	BUG_ON(th == NULL);
 
+	pr_debug("tcp_packet: ");
 	spin_lock_bh(&ct->lock);
 	old_state = ct->proto.tcp.state;
 	dir = CTINFO2DIR(ctinfo);
 	index = get_conntrack_index(th);
 	new_state = tcp_conntracks[dir][index][old_state];
 	tuple = &ct->tuplehash[dir].tuple;
+	pr_debug("dir=%u, seq=%u ack=%u win=%u end=%u\n",
+		 dir, ntohl(th->seq), ntohl(th->ack_seq), ntohs(th->window),
+		 segment_seq_plus_len(ntohl(th->seq), skb->len, dataoff, th));
 
 	switch (new_state) {
 	case TCP_CONNTRACK_SYN_SENT: