diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c
--- a/sys/kern/kern_jail.c
+++ b/sys/kern/kern_jail.c
@@ -4436,6 +4436,10 @@
     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
     NULL, PR_ALLOW_MOUNT, sysctl_jail_default_allow, "I",
     "Processes in jail can mount/unmount jail-friendly file systems (deprecated)");
+SYSCTL_PROC(_security_jail, OID_AUTO, mlock_allowed,
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
+    NULL, PR_ALLOW_MLOCK, sysctl_jail_default_allow, "I",
+    "Processes in jail can lock/unlock physical pages in memory");
 
 static int
 sysctl_jail_default_level(SYSCTL_HANDLER_ARGS)