diff --git a/Casks/firefox-cn.rb b/Casks/firefox-cn.rb
index 680a2d454..3ba3c1f48 100644
--- a/Casks/firefox-cn.rb
+++ b/Casks/firefox-cn.rb
@@ -4,6 +4,7 @@ class FirefoxCn < Cask
 
   url 'https://download.mozilla.org/?product=firefox-latest&os=osx&lang=zh-CN'
   homepage 'https://www.mozilla.org/zh-CN/firefox/'
+  license :oss
 
   app 'Firefox.app'
 end