diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index 9a8970b..98e0fd2 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -438,6 +438,7 @@
 	NET_CIPSOV4_RBM_STRICTVALID=121,
 	NET_TCP_AVAIL_CONG_CONTROL=122,
 	NET_TCP_ALLOWED_CONG_CONTROL=123,
+	NET_TCP_MAX_SSTHRESH=124,
 };
 
 enum {