diff --git a/multiple-cursors-core.el b/multiple-cursors-core.el
index 5e9ed76..2c255c1 100644
--- a/multiple-cursors-core.el
+++ b/multiple-cursors-core.el
@@ -575,9 +575,11 @@ from being executed if in multiple-cursors-mode."
            (overlay-put cursor 'kill-ring kill-ring)
            (overlay-put cursor 'kill-ring-yank-pointer kill-ring-yank-pointer)))))))
 
-(defvar mc/list-file (locate-user-emacs-file ".mc-lists.el")
+(defcustom mc/list-file (locate-user-emacs-file ".mc-lists.el")
   "The position of the file that keeps track of your preferences
-for running commands with multiple cursors.")
+for running commands with multiple cursors."
+  :type 'file
+  :group 'multiple-cursors)
 
 (defun mc/dump-list (list-symbol)
   "Insert (setq 'LIST-SYMBOL LIST-VALUE) to current buffer."