diff --git a/Casks/virtualbox431293733.rb b/Casks/virtualbox431293733.rb
index d51570cd8..0f117b701 100644
--- a/Casks/virtualbox431293733.rb
+++ b/Casks/virtualbox431293733.rb
@@ -1,4 +1,4 @@
-class Virtualbox431293733 < Cask
+cask :v1 => 'virtualbox431293733' do
   version '4.3.12-93733'
   sha256 'a9d9e3b3217177bc175839747de663ba25886f71e97a9c35ad802f618f11e23e'