Index: lib/libc/sys/shmctl.2
===================================================================
--- lib/libc/sys/shmctl.2
+++ lib/libc/sys/shmctl.2
@@ -72,15 +72,18 @@
 .It Dv IPC_RMID
 Removes the segment from the system.
 The removal will not take
-effect until all processes having attached the segment have exited;
-however, once the IPC_RMID operation has taken place, no further
-processes will be allowed to attach the segment.
+effect until all processes having attached the segment have exited.
 For the operation
 to succeed, the calling process's effective uid must match
 .Fa shm_perm.uid
 or
 .Fa shm_perm.cuid ,
 or the process must have superuser privileges.
+Unless the
+.Va kern.ipc.shm_allow_removed
+.Xr sysctl 3
+variable has been set to 0, once the IPC_RMID operation has taken place,
+no further processes will be allowed to attach the segment.
 .\" .It Dv SHM_LOCK
 .\" Locks the segment in memory.  The calling process must have
 .\" superuser privileges. Not implemented in FreeBSD.
Index: sys/kern/sysv_shm.c
===================================================================
--- sys/kern/sysv_shm.c
+++ sys/kern/sysv_shm.c
@@ -162,7 +162,7 @@
 };
 
 static int shm_use_phys;
-static int shm_allow_removed;
+static int shm_allow_removed = 1;
 
 SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RWTUN, &shminfo.shmmax, 0,
     "Maximum shared memory segment size");