diff --git a/etc/NEWS b/etc/NEWS
index 850854edfa4..551aea411ea 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1936,6 +1936,9 @@ Previously it produced a nonsense value, -1, that was never intended.
 
 * Lisp Changes in Emacs 29.1
 
+---
+** vc-mtn (the backend for Monotone) has been made obsolete.
+
 +++
 ** 'gui-set-selection' can now specify different values for different data types.
 If DATA is a string, then its text properties are searched for values
diff --git a/lisp/vc/vc-mtn.el b/lisp/obsolete/vc-mtn.el
similarity index 99%
rename from lisp/vc/vc-mtn.el
rename to lisp/obsolete/vc-mtn.el
index 20fbf92bb12..cd56b290072 100644
--- a/lisp/vc/vc-mtn.el
+++ b/lisp/obsolete/vc-mtn.el
@@ -5,6 +5,7 @@
 ;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
 ;; Keywords: vc
 ;; Package: vc
+;; Obsolete-since: 29.1
 
 ;; This file is part of GNU Emacs.