diff --git a/Casks/firefox-nightly.rb b/Casks/firefox-nightly.rb
index 7da77c8f2..1132e7d44 100644
--- a/Casks/firefox-nightly.rb
+++ b/Casks/firefox-nightly.rb
@@ -1,5 +1,5 @@
 class FirefoxNightly < Cask
-  url 'http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-trunk/firefox-33.0a1.en-US.mac.dmg'
+  url 'http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-trunk/firefox-34.0a1.en-US.mac.dmg'
   homepage 'https://nightly.mozilla.org/'
   version '33.0a1'
   sha256 :no_check