diff --git a/Casks/keyremap4macbook-mountainlion.rb b/Casks/keyremap4macbook-mountainlion.rb
index 0fa312655..b46f36a0a 100644
--- a/Casks/keyremap4macbook-mountainlion.rb
+++ b/Casks/keyremap4macbook-mountainlion.rb
@@ -4,6 +4,7 @@ class Keyremap4macbookMountainlion < Cask
 
   url "https://pqrs.org/macosx/keyremap4macbook/files/KeyRemap4MacBook-#{version}.dmg"
   homepage 'https://pqrs.org/macosx/keyremap4macbook/'
+  license :unknown
 
   pkg 'KeyRemap4MacBook.pkg'
 end