diff --git a/etc/edt-user.el b/etc/edt-user.el
index 0ecd818ec78..2852f936f22 100644
--- a/etc/edt-user.el
+++ b/etc/edt-user.el
@@ -1,4 +1,4 @@
-;;; edt-user.el --- Sample user customizations for Emacs EDT emulation
+;;; edt-user.el --- Sample user customizations for Emacs EDT emulation -*- lexical-binding: t -*-
 
 ;; Copyright (C) 1986, 1992-1993, 2000-2020 Free Software Foundation,
 ;; Inc.