diff --git a/Casks/moscow-ml.rb b/Casks/moscow-ml.rb
index 943883c85..7003cd28a 100644
--- a/Casks/moscow-ml.rb
+++ b/Casks/moscow-ml.rb
@@ -4,6 +4,7 @@ class MoscowMl < Cask
 
   url "https://github.com/kfl/mosml/releases/download/ver-#{version}/mosml-#{version}.pkg"
   homepage 'http://mosml.org/'
+  license :oss
 
   pkg "mosml-#{version}.pkg"
   uninstall :pkgutil => 'org.mosml'