diff --git a/newlib/libc/sys/rtems/include/netinet/tcp.h b/newlib/libc/sys/rtems/include/netinet/tcp.h
index 29c1e376c..e7c47e85b 100644
--- a/newlib/libc/sys/rtems/include/netinet/tcp.h
+++ b/newlib/libc/sys/rtems/include/netinet/tcp.h
@@ -310,7 +310,7 @@ struct tcphdr {
 #define TCP_RACK_PACING_BETA_ECN 1139	/* Changing the beta for ecn with pacing */
 #define TCP_RACK_TIMER_SLOP 1140	/* Set or get the timer slop used */
 #define TCP_RACK_DSACK_OPT 1141		/* How do we setup rack timer DSACK options bit 1/2 */
-
+#define TCP_RACK_ENABLE_HYSTART 1142	/* Do we allow hystart in the CC modules */
 /* Start of reserved space for third-party user-settable options. */
 #define	TCP_VENDOR	SO_VENDOR