diff --git a/lisp/emulation/edt-lk201.el b/lisp/emulation/edt-lk201.el
index c922e00f8f6..f7b2c0c93ea 100644
--- a/lisp/emulation/edt-lk201.el
+++ b/lisp/emulation/edt-lk201.el
@@ -1,4 +1,4 @@
-;;; edt-lk201.el --- enhanced EDT keypad mode emulation for LK-201 keyboards
+;;; edt-lk201.el --- enhanced EDT keypad mode emulation for LK-201 keyboards  -*- lexical-binding: t -*-
 
 ;; Copyright (C) 1986, 1992-1993, 1995, 2001-2020 Free Software
 ;; Foundation, Inc.
diff --git a/lisp/emulation/edt-pc.el b/lisp/emulation/edt-pc.el
index aa31d5bc32a..53fc9886b77 100644
--- a/lisp/emulation/edt-pc.el
+++ b/lisp/emulation/edt-pc.el
@@ -1,4 +1,4 @@
-;;; edt-pc.el --- enhanced EDT keypad mode emulation for PC 101 keyboards
+;;; edt-pc.el --- enhanced EDT keypad mode emulation for PC 101 keyboards  -*- lexical-binding: t -*-
 
 ;; Copyright (C) 1986, 1994-1995, 2001-2020 Free Software Foundation,
 ;; Inc.
diff --git a/lisp/emulation/edt-vt100.el b/lisp/emulation/edt-vt100.el
index 199212d2227..420d29b6aab 100644
--- a/lisp/emulation/edt-vt100.el
+++ b/lisp/emulation/edt-vt100.el
@@ -1,4 +1,4 @@
-;;; edt-vt100.el --- enhanced EDT keypad mode emulation for VT series terminals
+;;; edt-vt100.el --- enhanced EDT keypad mode emulation for VT series terminals  -*- lexical-binding: t -*-
 
 ;; Copyright (C) 1986, 1992-1993, 1995, 2002-2020 Free Software
 ;; Foundation, Inc.