diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index a242f8874629..7fdf222a0bdf 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -22,7 +22,7 @@
 #include <linux/gfp.h>
 #include <net/tcp.h>
 
-u32 tcp_retransmit_stamp(const struct sock *sk)
+static u32 tcp_retransmit_stamp(const struct sock *sk)
 {
 	u32 start_ts = tcp_sk(sk)->retrans_stamp;