diff --git a/doc/emacs/ack.texi b/doc/emacs/ack.texi
index 3eac9b31e35..eebab8acaa8 100644
--- a/doc/emacs/ack.texi
+++ b/doc/emacs/ack.texi
@@ -839,7 +839,8 @@ facility.  He also wrote @code{ebrowse}, the C@t{++} browser;
 and @file{rx.el}, a regular expression constructor.
 
 @item
-Stefan Monnier was the Emacs (co-)maintainer from Emacs 23 onwards.  He added
+Stefan Monnier was the Emacs (co-)maintainer from Emacs 23 until
+late in the development of 25.1.  He added
 support for Arch and Subversion to VC, re-wrote much of the Emacs server
 to use the built-in networking primitives, and re-wrote the abbrev and
 minibuffer completion code for Emacs 23.  He also wrote @code{PCL-CVS},