diff --git a/Casks/emacs-app-nightly.rb b/Casks/emacs-app-nightly.rb
index b5fe47b8..8597d368 100644
--- a/Casks/emacs-app-nightly.rb
+++ b/Casks/emacs-app-nightly.rb
@@ -1,10 +1,10 @@
 # frozen_string_literal: true
 
 cask 'emacs-app-nightly' do
-  version '2021-12-20.aa1fdb3.master'
+  version '2021-12-21.4b7e734.master'
 
-  sha256 '047ff1b9da76f47f1e05bd373cc6295f43f9835af9ed4ba07d4d3e1557f10185'
-  url 'https://github.com/jimeh/emacs-builds/releases/download/Emacs.2021-12-20.aa1fdb3.master/Emacs.2021-12-20.aa1fdb3.master.macOS-10-15.x86_64.dmg'
+  sha256 '0acf0c02cf2fd8b33ec893f6aaac25ec9d57454779c52c608a721f1127bf36ab'
+  url 'https://github.com/jimeh/emacs-builds/releases/download/Emacs.2021-12-21.4b7e734.master/Emacs.2021-12-21.4b7e734.master.macOS-10-15.x86_64.dmg'
 
   name 'Emacs'
   desc 'GNU Emacs text editor (nightly build)'