diff --git a/Casks/z/zotero.rb b/Casks/z/zotero.rb
index dc8a5ecd49..468e9b69d8 100644
--- a/Casks/z/zotero.rb
+++ b/Casks/z/zotero.rb
@@ -14,6 +14,7 @@ cask "zotero" do
 
   auto_updates true
   conflicts_with cask: "zotero-beta"
+  depends_on macos: ">= :el_capitan"
 
   app "Zotero.app"