diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 7d2dc01..5bc3c30 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2441,6 +2441,20 @@
 	return window;
 }
 
+static void tcp_skb_collapse_tstamp(struct sk_buff *skb,
+				    const struct sk_buff *next_skb)
+{
+	const struct skb_shared_info *next_shinfo = skb_shinfo(next_skb);
+	u8 tsflags = next_shinfo->tx_flags & SKBTX_ANY_TSTAMP;
+
+	if (unlikely(tsflags)) {
+		struct skb_shared_info *shinfo = skb_shinfo(skb);
+
+		shinfo->tx_flags |= tsflags;
+		shinfo->tskey = next_shinfo->tskey;
+	}
+}
+
 /* Collapses two adjacent SKB's during retransmission. */
 static void tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb)
 {
@@ -2484,6 +2498,8 @@
 
 	tcp_adjust_pcount(sk, next_skb, tcp_skb_pcount(next_skb));
 
+	tcp_skb_collapse_tstamp(skb, next_skb);
+
 	sk_wmem_free_skb(sk, next_skb);
 }