diff --git a/src/m/template.h b/src/m/template.h
index 9b8d2d63055..2807cd913ec 100644
--- a/src/m/template.h
+++ b/src/m/template.h
@@ -69,11 +69,14 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    reasonable place to select for it is in the machine description file.  */
 #define NO_SOCK_SIGIO
 
-/* After adding support for a new system, modify the large case
-   statement in the `configure' script to recognize reasonable
+/* After adding support for a new machine, modify the large case
+   statement in configure.in to recognize reasonable
    configuration names, and add a description of the system to
    `etc/MACHINES'.
 
+   Check for any tests of $machine in configure.in, and add an entry
+   for the new machine if needed.
+
    If you've just fixed a problem in an existing configuration file,
    you should also check `etc/MACHINES' to make sure its descriptions
    of known problems in that configuration should be updated.  */
diff --git a/src/s/template.h b/src/s/template.h
index 16df03092d2..f355d67b8c6 100644
--- a/src/s/template.h
+++ b/src/s/template.h
@@ -133,10 +133,13 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 /* ============================================================ */
 
 /* After adding support for a new system, modify the large case
-   statement in the `configure' script to recognize reasonable
+   statement in configure.in to recognize reasonable
    configuration names, and add a description of the system to
    `etc/MACHINES'.
 
+   Check for any tests of $opsys in configure.in, and add an entry
+   for the new system if needed.
+
    If you've just fixed a problem in an existing configuration file,
    you should also check `etc/MACHINES' to make sure its descriptions
    of known problems in that configuration should be updated.  */