diff --git a/Casks/f/firefox.rb b/Casks/f/firefox.rb
index 73b9088230..5c5ad3dabe 100644
--- a/Casks/f/firefox.rb
+++ b/Casks/f/firefox.rb
@@ -223,7 +223,7 @@ cask "firefox" do
     "homebrew/cask-versions/firefox-cn",
     "homebrew/cask-versions/firefox-esr",
   ]
-  depends_on macos: ">= :sierra"
+  depends_on macos: ">= :catalina"
 
   app "Firefox.app"
   # shim script (https://github.com/Homebrew/homebrew-cask/issues/18809)