diff --git a/Casks/hirundo.rb b/Casks/hirundo.rb
index a3ed0c982..02b0170db 100644
--- a/Casks/hirundo.rb
+++ b/Casks/hirundo.rb
@@ -7,5 +7,7 @@ cask 'hirundo' do
   homepage 'https://stylemac.com/hirundo/'
   license :commercial
 
+  depends_on macos: '>= :el_capitan'
+
   app 'Hirundo.app'
 end