#if TCPDEBUG
__private_extern__ int tcpconsdebug = 0;
-SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcpconsdebug, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcpconsdebug, CTLFLAG_RW | CTLFLAG_LOCKED,
&tcpconsdebug, 0, "Turn tcp debugging on or off");
#endif