diff --git a/Casks/firefoxdeveloperedition.rb b/Casks/firefoxdeveloperedition.rb
index 593b7e0a6..508eb8a08 100644
--- a/Casks/firefoxdeveloperedition.rb
+++ b/Casks/firefoxdeveloperedition.rb
@@ -26,6 +26,10 @@ cask 'firefoxdeveloperedition' do
     'zh-CN'
   end
 
+  language 'de' do
+    'de'
+  end
+
   url "https://download.mozilla.org/?product=firefox-aurora-latest-#{language == 'en-US' ? 'ssl' : 'l10n'}&os=osx&lang=#{language}"
   name 'Mozilla Firefox Developer Edition'
   homepage 'https://www.mozilla.org/firefox/developer/'