--- linux-4.9.37/include/net/netns/ipv4.h	2017-07-12 16:42:41.000000000 +0300
+++ linux-4.9.y/include/net/netns/ipv4.h	2021-06-07 13:01:34.000000000 +0300
@@ -94,6 +94,7 @@
 #endif
 	int sysctl_tcp_mtu_probing;
 	int sysctl_tcp_base_mss;
+	int sysctl_tcp_min_snd_mss;
 	int sysctl_tcp_probe_threshold;
 	u32 sysctl_tcp_probe_interval;