diff --git a/Library/Homebrew/cask/download.rb b/Library/Homebrew/cask/download.rb
index 976e440dee..6912edceda 100644
--- a/Library/Homebrew/cask/download.rb
+++ b/Library/Homebrew/cask/download.rb
@@ -24,6 +24,8 @@ module Cask
 
     sig { override.returns(T.nilable(::URL)) }
     def url
+      return if cask.url.nil?
+
       @url ||= ::URL.new(cask.url.to_s, cask.url.specs)
     end
 
diff --git a/Library/Homebrew/cmd/fetch.rb b/Library/Homebrew/cmd/fetch.rb
index 569239ad19..de6751ad6c 100644
--- a/Library/Homebrew/cmd/fetch.rb
+++ b/Library/Homebrew/cmd/fetch.rb
@@ -167,6 +167,11 @@ module Homebrew
           SimulateSystem.with os: os, arch: arch do
             cask = Cask::CaskLoader.load(ref)
 
+            if cask.depends_on.macos&.satisfied? == false
+              opoo "#{cask.token}: #{cask.depends_on.macos.message(type: :cask)}"
+              next
+            end
+
             quarantine = args.quarantine?
             quarantine = true if quarantine.nil?