diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index a778ee0..e64f4c6 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -105,6 +105,7 @@
 #define TCP_COOKIE_TRANSACTIONS	15	/* TCP Cookie Transactions */
 #define TCP_THIN_LINEAR_TIMEOUTS 16      /* Use linear timeouts for thin streams*/
 #define TCP_THIN_DUPACK         17      /* Fast retrans. after 1 dupack */
+#define TCP_USER_TIMEOUT	18	/* How long for loss retry before timeout */
 
 /* for TCP_INFO socket option */
 #define TCPI_OPT_TIMESTAMPS	1