diff --git a/usr.sbin/mountd/mountd.8 b/usr.sbin/mountd/mountd.8
--- a/usr.sbin/mountd/mountd.8
+++ b/usr.sbin/mountd/mountd.8
@@ -25,7 +25,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd July 5, 2024
+.Dd December 16, 2024
 .Dt MOUNTD 8
 .Os
 .Sh NAME
@@ -35,7 +35,7 @@
 mount requests
 .Sh SYNOPSIS
 .Nm
-.Op Fl 2AdelNnRrSs
+.Op Fl 2AadelNnRrSs
 .Op Fl h Ar bindip
 .Op Fl p Ar port
 .Op Ar exportsfile ...
@@ -70,6 +70,17 @@
 the subtree below the directory exported.
 (See
 .Xr exports 5 )
+.It Fl a
+Enforce the check for an exported directory being a file
+system mount point, if the
+.Fl -alldirs
+option is specified in
+.Xr exports 5
+for the export file line.
+With this option, the exports line will fail, whereas
+without this option, a warning will be generated by
+.Xr syslog 8 ,
+but the export will be done.
 .It Fl d
 Output debugging information.
 .Nm
@@ -244,7 +255,8 @@
 .Xr jail 8 ,
 .Xr nfsd 8 ,
 .Xr rpcbind 8 ,
-.Xr showmount 8
+.Xr showmount 8 ,
+.Xr syslog 8
 .Sh HISTORY
 The
 .Nm