diff --git a/lisp/mail/rmailmsc.el b/lisp/mail/rmailmsc.el
index 9f825d9325a..98926d8117e 100644
--- a/lisp/mail/rmailmsc.el
+++ b/lisp/mail/rmailmsc.el
@@ -24,6 +24,7 @@
 
 ;;; Code:
 
+;;;###autoload
 (defun set-rmail-inbox-list (file-name)
   "Set the inbox list of the current RMAIL file to FILE-NAME.
 You can specify one file name, or several names separated by commas.