diff --git a/Casks/emacs-app-nightly.rb b/Casks/emacs-app-nightly.rb
index 55738d41..0a2f3beb 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 '2021-09-05.80d318a.master'
+  version '2021-09-06.4bd3a40.master'
 
-  sha256 '9db49052ae5de47cbd14113401831a148ffad6b17bc78f8440951b5faf0d8497'
-  url 'https://github.com/jimeh/emacs-builds/releases/download/Emacs.2021-09-05.80d318a.master/Emacs.2021-09-05.80d318a.master.macOS-10-15.x86_64.dmg'
+  sha256 '355dbe06d6e3303606f3669fe9ec158ef3fdacf2f980b0e669dde203dfa273ad'
+  url 'https://github.com/jimeh/emacs-builds/releases/download/Emacs.2021-09-06.4bd3a40.master/Emacs.2021-09-06.4bd3a40.master.macOS-10-15.x86_64.dmg'
 
   name 'Emacs'
   desc 'GNU Emacs text editor (nightly build)'