diff --git a/share/man/man5/src.conf.5 b/share/man/man5/src.conf.5
--- a/share/man/man5/src.conf.5
+++ b/share/man/man5/src.conf.5
@@ -1,6 +1,6 @@
 .\" DO NOT EDIT-- this file is @generated by tools/build/options/makeman.
 .\" $FreeBSD$
-.Dd February 2, 2021
+.Dd February 10, 2021
 .Dt SRC.CONF 5
 .Os
 .Sh NAME
@@ -630,9 +630,11 @@
 .It Va WITHOUT_FLOPPY
 Set to not build or install programs
 for operating floppy disk driver.
-.It Va WITHOUT_FMTREE
-Set to not build and install
+.It Va WITH_FMTREE
+Set to build and install
 .Pa /usr/sbin/fmtree .
+This option is deprecated, and will be gone in
+.Fx 14.0 .
 .It Va WITHOUT_FORMAT_EXTENSIONS
 Set to not enable
 .Fl fformat-extensions
diff --git a/share/mk/src.opts.mk b/share/mk/src.opts.mk
--- a/share/mk/src.opts.mk
+++ b/share/mk/src.opts.mk
@@ -99,7 +99,6 @@
     FILE \
     FINGER \
     FLOPPY \
-    FMTREE \
     FORTH \
     FP_LIBC \
     FREEBSD_UPDATE \
@@ -202,6 +201,7 @@
     CLANG_FORMAT \
     DTRACE_TESTS \
     EXPERIMENTAL \
+    FMTREE \
     HESIOD \
     LIBSOFT \
     LOADER_FIREWIRE \
diff --git a/tools/build/options/WITH_FMTREE b/tools/build/options/WITH_FMTREE
new file mode 100644
--- /dev/null
+++ b/tools/build/options/WITH_FMTREE
@@ -0,0 +1,5 @@
+.\" $FreeBSD$
+Set to build and install
+.Pa /usr/sbin/fmtree .
+This option is deprecated, and will be gone in
+.Fx 14.0 .
diff --git a/usr.sbin/fmtree/mtree.8 b/usr.sbin/fmtree/mtree.8
--- a/usr.sbin/fmtree/mtree.8
+++ b/usr.sbin/fmtree/mtree.8
@@ -28,7 +28,7 @@
 .\"     From: @(#)mtree.8	8.2 (Berkeley) 12/11/93
 .\" $FreeBSD$
 .\"
-.Dd June 16, 2007
+.Dd February 10, 2021
 .Dt MTREE 8
 .Os
 .Sh NAME
@@ -362,6 +362,10 @@
 .Fl n
 .Fl k
 .Cm uname,gname,mode,nochange.
+.Sh DEPRECATION NOTICE
+.Nm fmtree
+is deprecated, and will be gone in
+.Fx 14.0 .
 .Sh SEE ALSO
 .Xr chflags 1 ,
 .Xr chgrp 1 ,