diff --git a/Casks/swish.rb b/Casks/swish.rb
index b326d49fcca..90d0ed59a06 100644
--- a/Casks/swish.rb
+++ b/Casks/swish.rb
@@ -7,5 +7,7 @@ cask 'swish' do
   name 'Swish'
   homepage 'https://highlyopinionated.co/swish/'
 
+  depends_on macos: '>= :high_sierra'
+
   app 'Swish.app'
 end