diff --git a/Casks/rss.rb b/Casks/rss.rb
index 9be5ec8ebc5..edfb759fa2d 100644
--- a/Casks/rss.rb
+++ b/Casks/rss.rb
@@ -4,6 +4,7 @@ class Rss < Cask
 
   url 'http://www.rssapplication.com/RSS.zip'
   homepage 'http://www.rssapplication.com/'
+  license :unknown
 
   app 'RSS.app'
 end