diff --git a/Casks/firefox-tw.rb b/Casks/firefox-zh-tw.rb
similarity index 94%
rename from Casks/firefox-tw.rb
rename to Casks/firefox-zh-tw.rb
index c19ef5866..3c2bce7f8 100644
--- a/Casks/firefox-tw.rb
+++ b/Casks/firefox-zh-tw.rb
@@ -1,4 +1,4 @@
-cask 'firefox-tw' do
+cask 'firefox-zh-tw' do
   version '43.0.3'
   sha256 'a81f10b0104a27d9d0b81e9f817fc6bd82175e56859166273dfece47d6076414'
 
@@ -8,7 +8,7 @@ cask 'firefox-tw' do
   license :mpl
 
   app 'Firefox.app'
-  
+
   zap :delete => [
                   '~/Library/Application Support/Firefox',
                   '~/Library/Caches/Firefox',