diff --git a/Casks/istat-menus4.rb b/Casks/istat-menus4.rb
index e30969aa7..ae758e197 100644
--- a/Casks/istat-menus4.rb
+++ b/Casks/istat-menus4.rb
@@ -4,6 +4,7 @@ class IstatMenus4 < Cask
 
   url "http://s3.amazonaws.com/bjango/files/istatmenus4/istatmenus#{version}.zip"
   homepage 'http://bjango.com/mac/istatmenus/'
+  license :unknown
 
   app 'iStat Menus.app'
 end