diff --git a/pkgs/applications/editors/emacs/build-support/elpa2nix.el b/pkgs/applications/editors/emacs/build-support/elpa2nix.el
index 5b363b7b6640..4622442f7492 100644
--- a/pkgs/applications/editors/emacs/build-support/elpa2nix.el
+++ b/pkgs/applications/editors/emacs/build-support/elpa2nix.el
@@ -1,3 +1,5 @@
+;; -*- lexical-binding: t; -*-
+
 (require 'package)
 (package-initialize)
 
diff --git a/pkgs/applications/editors/emacs/build-support/melpa2nix.el b/pkgs/applications/editors/emacs/build-support/melpa2nix.el
index f2cb334f4c41..28ae9b65c5da 100644
--- a/pkgs/applications/editors/emacs/build-support/melpa2nix.el
+++ b/pkgs/applications/editors/emacs/build-support/melpa2nix.el
@@ -1,3 +1,5 @@
+;; -*- lexical-binding: t; -*-
+
 (require 'package-recipe)
 (require 'package-build)
 
diff --git a/pkgs/applications/editors/emacs/build-support/mk-wrapper-subdirs.el b/pkgs/applications/editors/emacs/build-support/mk-wrapper-subdirs.el
index 7d30400a5c65..caca513047a4 100644
--- a/pkgs/applications/editors/emacs/build-support/mk-wrapper-subdirs.el
+++ b/pkgs/applications/editors/emacs/build-support/mk-wrapper-subdirs.el
@@ -1,3 +1,5 @@
+;; -*- lexical-binding: t; -*-
+
 (defmacro mk-subdirs-expr (path)
   `(setq load-path
          (delete-dups (append '(,path)