diff --git a/include/net/tcp.h b/include/net/tcp.h
index 8b404b1..c209361 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -660,7 +660,7 @@
 	/* new value of cwnd after loss (optional) */
 	u32  (*undo_cwnd)(struct sock *sk);
 	/* hook for packet ack accounting (optional) */
-	void (*pkts_acked)(struct sock *sk, u32 num_acked, ktime_t last);
+	void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us);
 	/* get info for inet_diag (optional) */
 	void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb);