diff --git a/Casks/thunderbird-it.rb b/Casks/thunderbird-it.rb
index bee5fd6cb..0580dcb49 100644
--- a/Casks/thunderbird-it.rb
+++ b/Casks/thunderbird-it.rb
@@ -1,4 +1,4 @@
-class ThunderbirdIt < Cask
+cask :v1 => 'thunderbird-it' do
   version '31.2.0'
   sha256 '28bacc4d40ddc1d81eacb4b921006737a58fa69732b5afcbe596a4ec5709bc90'