diff --git a/Library/Homebrew/cask/cask.rb b/Library/Homebrew/cask/cask.rb
index 38c0ceb09a..4336cff60a 100644
--- a/Library/Homebrew/cask/cask.rb
+++ b/Library/Homebrew/cask/cask.rb
@@ -11,7 +11,7 @@ module Cask
     extend Searchable
     include Metadata
 
-    attr_reader :token, :sourcefile_path, :config
+    attr_reader :token, :sourcefile_path
 
     def self.each
       return to_enum unless block_given?
@@ -31,7 +31,7 @@ module Cask
       @tap
     end
 
-    def initialize(token, sourcefile_path: nil, tap: nil, config: Config.global, &block)
+    def initialize(token, sourcefile_path: nil, tap: nil, config: nil, &block)
       @token = token
       @sourcefile_path = sourcefile_path
       @tap = tap
@@ -77,6 +77,14 @@ module Cask
       metadata_master_container_path.join(*installed_version, "Casks", "#{token}.rb")
     end
 
+    def config
+      @config ||= Config.for_cask(self)
+    end
+
+    def config_path
+      metadata_master_container_path/"dirs.json"
+    end
+
     def outdated?(greedy = false)
       !outdated_versions(greedy).empty?
     end
diff --git a/Library/Homebrew/cask/config.rb b/Library/Homebrew/cask/config.rb
index 07ffee2ead..ed40737b47 100644
--- a/Library/Homebrew/cask/config.rb
+++ b/Library/Homebrew/cask/config.rb
@@ -1,12 +1,8 @@
+require "json"
+
 module Cask
-  class Config
-    def self.global
-      @global ||= new
-    end
-
-    attr_reader :binarydir
-
-    def initialize(
+  class Config < DelegateClass(Hash)
+    DEFAULT_DIRS = {
       appdir:               "/Applications",
       prefpanedir:          "~/Library/PreferencePanes",
       qlplugindir:          "~/Library/QuickLook",
@@ -19,47 +15,51 @@ module Cask
       audio_unit_plugindir: "~/Library/Audio/Plug-Ins/Components",
       vst_plugindir:        "~/Library/Audio/Plug-Ins/VST",
       vst3_plugindir:       "~/Library/Audio/Plug-Ins/VST3",
-      screen_saverdir:      "~/Library/Screen Savers"
-    )
+      screen_saverdir:      "~/Library/Screen Savers",
+    }.freeze
 
-      self.appdir               = appdir
-      self.prefpanedir          = prefpanedir
-      self.qlplugindir          = qlplugindir
-      self.dictionarydir        = dictionarydir
-      self.fontdir              = fontdir
-      self.colorpickerdir       = colorpickerdir
-      self.servicedir           = servicedir
-      self.input_methoddir      = input_methoddir
-      self.internet_plugindir   = internet_plugindir
-      self.audio_unit_plugindir = audio_unit_plugindir
-      self.vst_plugindir        = vst_plugindir
-      self.vst3_plugindir       = vst3_plugindir
-      self.screen_saverdir      = screen_saverdir
-
-      # `binarydir` is not customisable.
-      @binarydir = HOMEBREW_PREFIX/"bin"
+    def self.global
+      @global ||= new
     end
 
-    [
-      :appdir,
-      :prefpanedir,
-      :qlplugindir,
-      :dictionarydir,
-      :fontdir,
-      :colorpickerdir,
-      :servicedir,
-      :input_methoddir,
-      :internet_plugindir,
-      :audio_unit_plugindir,
-      :vst_plugindir,
-      :vst3_plugindir,
-      :screen_saverdir,
-    ].each do |dir|
-      attr_reader dir
+    def self.for_cask(cask)
+      if cask.config_path.exist?
+        from_file(cask.config_path)
+      else
+        global
+      end
+    end
+
+    def self.from_file(path)
+      config = begin
+        JSON.parse(File.read(path))
+      rescue JSON::ParserError => e
+        raise e, "Cannot parse #{path}: #{e}", e.backtrace
+      end
+
+      new(Hash[config.map { |k, v| [k.to_sym, v] }])
+    end
+
+    def initialize(**dirs)
+      super(Hash[DEFAULT_DIRS.map { |(k, v)| [k, Pathname(dirs.fetch(k, v)).expand_path] }])
+    end
+
+    def binarydir
+      @binarydir ||= HOMEBREW_PREFIX/"bin"
+    end
+
+    DEFAULT_DIRS.keys.each do |dir|
+      define_method(dir) do
+        self[dir]
+      end
 
       define_method(:"#{dir}=") do |path|
-        instance_variable_set(:"@#{dir}", Pathname(path).expand_path)
+        self[dir] = Pathname(path).expand_path
       end
     end
+
+    def write(path)
+      path.atomic_write(to_json)
+    end
   end
 end
diff --git a/Library/Homebrew/cask/installer.rb b/Library/Homebrew/cask/installer.rb
index 5c2b58ebd2..74f1664972 100644
--- a/Library/Homebrew/cask/installer.rb
+++ b/Library/Homebrew/cask/installer.rb
@@ -39,7 +39,7 @@ module Cask
     end
 
     attr_predicate :binaries?, :force?, :skip_cask_deps?, :require_sha?,
-                   :upgrade?, :verbose?, :installed_as_dependency?,
+                   :reinstall?, :upgrade?, :verbose?, :installed_as_dependency?,
                    :quarantine?
 
     def self.print_caveats(cask)
@@ -79,7 +79,7 @@ module Cask
     def install
       odebug "Cask::Installer#install"
 
-      if @cask.installed? && !force? && !@reinstall && !upgrade?
+      if @cask.installed? && !force? && !reinstall? && !upgrade?
         raise CaskAlreadyInstalledError, @cask
       end
 
@@ -87,7 +87,7 @@ module Cask
 
       print_caveats
       fetch
-      uninstall_existing_cask if @reinstall
+      uninstall_existing_cask if reinstall?
 
       oh1 "Installing Cask #{Formatter.identifier(@cask)}"
       opoo "macOS's Gatekeeper has been disabled for this Cask" unless quarantine?
@@ -209,6 +209,8 @@ module Cask
         artifact.install_phase(command: @command, verbose: verbose?, force: force?)
         already_installed_artifacts.unshift(artifact)
       end
+
+      save_config_file
     rescue => e
       begin
         already_installed_artifacts.each do |artifact|
@@ -382,13 +384,23 @@ module Cask
       old_savedir&.rmtree
     end
 
+    def save_config_file
+      @cask.config.write(@cask.config_path)
+    end
+
     def uninstall
       oh1 "Uninstalling Cask #{Formatter.identifier(@cask)}"
       uninstall_artifacts(clear: true)
+      remove_config_file unless reinstall? || upgrade?
       purge_versioned_files
       purge_caskroom_path if force?
     end
 
+    def remove_config_file
+      FileUtils.rm_f @cask.config_path
+      @cask.config_path.parent.rmdir_if_possible
+    end
+
     def start_upgrade
       oh1 "Starting upgrade for Cask #{Formatter.identifier(@cask)}"
 
diff --git a/Library/Homebrew/test/cask/artifact/alt_target_spec.rb b/Library/Homebrew/test/cask/artifact/alt_target_spec.rb
index ef929154f6..b2808c420d 100644
--- a/Library/Homebrew/test/cask/artifact/alt_target_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/alt_target_spec.rb
@@ -11,7 +11,7 @@ describe Cask::Artifact::App, :cask do
     }
 
     let(:source_path) { cask.staged_path.join("Caffeine.app") }
-    let(:target_path) { Cask::Config.global.appdir.join("AnotherName.app") }
+    let(:target_path) { cask.config.appdir.join("AnotherName.app") }
 
     before do
       InstallHelper.install_without_artifacts(cask)
@@ -58,7 +58,7 @@ describe Cask::Artifact::App, :cask do
       expect(target_path).to be_a_directory
       expect(source_path).not_to exist
 
-      expect(Cask::Config.global.appdir.join("Caffeine Deluxe.app")).not_to exist
+      expect(cask.config.appdir.join("Caffeine Deluxe.app")).not_to exist
       expect(cask.staged_path.join("Caffeine Deluxe.app")).to be_a_directory
     end
 
diff --git a/Library/Homebrew/test/cask/artifact/app_spec.rb b/Library/Homebrew/test/cask/artifact/app_spec.rb
index 26abb19ad9..14917b4f42 100644
--- a/Library/Homebrew/test/cask/artifact/app_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/app_spec.rb
@@ -5,7 +5,7 @@ describe Cask::Artifact::App, :cask do
   let(:app) { cask.artifacts.find { |a| a.is_a?(described_class) } }
 
   let(:source_path) { cask.staged_path.join("Caffeine.app") }
-  let(:target_path) { Cask::Config.global.appdir.join("Caffeine.app") }
+  let(:target_path) { cask.config.appdir.join("Caffeine.app") }
 
   let(:install_phase) { app.install_phase(command: command, force: force) }
   let(:uninstall_phase) { app.uninstall_phase(command: command, force: force) }
@@ -53,7 +53,7 @@ describe Cask::Artifact::App, :cask do
       expect(target_path).to be_a_directory
       expect(source_path).not_to exist
 
-      expect(Cask::Config.global.appdir.join("Caffeine Deluxe.app")).not_to exist
+      expect(cask.config.appdir.join("Caffeine Deluxe.app")).not_to exist
       expect(cask.staged_path.join("Caffeine Deluxe.app")).to exist
     end
 
diff --git a/Library/Homebrew/test/cask/artifact/binary_spec.rb b/Library/Homebrew/test/cask/artifact/binary_spec.rb
index bd70904ebc..0aa60c38fe 100644
--- a/Library/Homebrew/test/cask/artifact/binary_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/binary_spec.rb
@@ -5,7 +5,7 @@ describe Cask::Artifact::Binary, :cask do
     end
   }
   let(:artifacts) { cask.artifacts.select { |a| a.is_a?(described_class) } }
-  let(:expected_path) { Cask::Config.global.binarydir.join("binary") }
+  let(:expected_path) { cask.config.binarydir.join("binary") }
 
   after do
     FileUtils.rm expected_path if expected_path.exist?
@@ -38,7 +38,7 @@ describe Cask::Artifact::Binary, :cask do
       end
     }
 
-    let(:expected_path) { Cask::Config.global.binarydir.join("naked_non_executable") }
+    let(:expected_path) { cask.config.binarydir.join("naked_non_executable") }
 
     it "makes the binary executable" do
       expect(FileUtils).to receive(:chmod)
diff --git a/Library/Homebrew/test/cask/artifact/generic_artifact_spec.rb b/Library/Homebrew/test/cask/artifact/generic_artifact_spec.rb
index ff28392175..83fb55fc58 100644
--- a/Library/Homebrew/test/cask/artifact/generic_artifact_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/generic_artifact_spec.rb
@@ -10,7 +10,7 @@ describe Cask::Artifact::Artifact, :cask do
   }
 
   let(:source_path) { cask.staged_path.join("Caffeine.app") }
-  let(:target_path) { Cask::Config.global.appdir.join("Caffeine.app") }
+  let(:target_path) { cask.config.appdir.join("Caffeine.app") }
 
   before do
     InstallHelper.install_without_artifacts(cask)
diff --git a/Library/Homebrew/test/cask/artifact/suite_spec.rb b/Library/Homebrew/test/cask/artifact/suite_spec.rb
index 87f821aea2..3f4a2d6dc8 100644
--- a/Library/Homebrew/test/cask/artifact/suite_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/suite_spec.rb
@@ -9,7 +9,7 @@ describe Cask::Artifact::Suite, :cask do
     end
   }
 
-  let(:target_path) { Cask::Config.global.appdir.join("Caffeine") }
+  let(:target_path) { cask.config.appdir.join("Caffeine") }
   let(:source_path) { cask.staged_path.join("Caffeine") }
 
   before do
diff --git a/Library/Homebrew/test/cask/artifact/two_apps_correct_spec.rb b/Library/Homebrew/test/cask/artifact/two_apps_correct_spec.rb
index a5375125ba..7381c832ba 100644
--- a/Library/Homebrew/test/cask/artifact/two_apps_correct_spec.rb
+++ b/Library/Homebrew/test/cask/artifact/two_apps_correct_spec.rb
@@ -11,10 +11,10 @@ describe Cask::Artifact::App, :cask do
     }
 
     let(:source_path_mini) { cask.staged_path.join("Caffeine Mini.app") }
-    let(:target_path_mini) { Cask::Config.global.appdir.join("Caffeine Mini.app") }
+    let(:target_path_mini) { cask.config.appdir.join("Caffeine Mini.app") }
 
     let(:source_path_pro) { cask.staged_path.join("Caffeine Pro.app") }
-    let(:target_path_pro) { Cask::Config.global.appdir.join("Caffeine Pro.app") }
+    let(:target_path_pro) { cask.config.appdir.join("Caffeine Pro.app") }
 
     before do
       InstallHelper.install_without_artifacts(cask)
@@ -52,7 +52,7 @@ describe Cask::Artifact::App, :cask do
       expect(target_path_mini).to be_a_directory
       expect(source_path_mini).not_to exist
 
-      expect(Cask::Config.global.appdir.join("Caffeine Deluxe.app")).not_to exist
+      expect(cask.config.appdir.join("Caffeine Deluxe.app")).not_to exist
       expect(cask.staged_path.join("Caffeine Deluxe.app")).to exist
     end
 
diff --git a/Library/Homebrew/test/cask/cmd/install_spec.rb b/Library/Homebrew/test/cask/cmd/install_spec.rb
index c3113e1662..1efe513b4c 100644
--- a/Library/Homebrew/test/cask/cmd/install_spec.rb
+++ b/Library/Homebrew/test/cask/cmd/install_spec.rb
@@ -21,11 +21,12 @@ describe Cask::Cmd::Install, :cask do
 
   it "allows staging and activation of multiple Casks at once" do
     described_class.run("local-transmission", "local-caffeine")
-
-    expect(Cask::CaskLoader.load(cask_path("local-transmission"))).to be_installed
-    expect(Cask::Config.global.appdir.join("Transmission.app")).to be_a_directory
-    expect(Cask::CaskLoader.load(cask_path("local-caffeine"))).to be_installed
-    expect(Cask::Config.global.appdir.join("Caffeine.app")).to be_a_directory
+    transmission = Cask::CaskLoader.load(cask_path("local-transmission"))
+    caffeine = Cask::CaskLoader.load(cask_path("local-caffeine"))
+    expect(transmission).to be_installed
+    expect(transmission.config.appdir.join("Transmission.app")).to be_a_directory
+    expect(caffeine).to be_installed
+    expect(caffeine.config.appdir.join("Caffeine.app")).to be_a_directory
   end
 
   it "skips double install (without nuking existing installation)" do
diff --git a/Library/Homebrew/test/cask/cmd/list_spec.rb b/Library/Homebrew/test/cask/cmd/list_spec.rb
index 2c819fcb30..7d63076e46 100644
--- a/Library/Homebrew/test/cask/cmd/list_spec.rb
+++ b/Library/Homebrew/test/cask/cmd/list_spec.rb
@@ -80,9 +80,9 @@ describe Cask::Cmd::List, :cask do
         described_class.run("local-transmission", "local-caffeine")
       }.to output(<<~EOS).to_stdout
         ==> Apps
-        #{Cask::Config.global.appdir.join("Transmission.app")} (#{Cask::Config.global.appdir.join("Transmission.app").abv})
+        #{transmission.config.appdir.join("Transmission.app")} (#{transmission.config.appdir.join("Transmission.app").abv})
         ==> Apps
-        Missing App: #{Cask::Config.global.appdir.join("Caffeine.app")}
+        Missing App: #{caffeine.config.appdir.join("Caffeine.app")}
       EOS
     end
   end
diff --git a/Library/Homebrew/test/cask/cmd/uninstall_spec.rb b/Library/Homebrew/test/cask/cmd/uninstall_spec.rb
index 215c9f9757..dc6a07e01d 100644
--- a/Library/Homebrew/test/cask/cmd/uninstall_spec.rb
+++ b/Library/Homebrew/test/cask/cmd/uninstall_spec.rb
@@ -51,9 +51,9 @@ describe Cask::Cmd::Uninstall, :cask do
     described_class.run("local-caffeine", "local-transmission")
 
     expect(caffeine).not_to be_installed
-    expect(Cask::Config.global.appdir.join("Transmission.app")).not_to exist
+    expect(caffeine.config.appdir.join("Transmission.app")).not_to exist
     expect(transmission).not_to be_installed
-    expect(Cask::Config.global.appdir.join("Caffeine.app")).not_to exist
+    expect(transmission.config.appdir.join("Caffeine.app")).not_to exist
   end
 
   it "calls `uninstall` before removing artifacts" do
@@ -69,7 +69,7 @@ describe Cask::Cmd::Uninstall, :cask do
     }.not_to raise_error
 
     expect(cask).not_to be_installed
-    expect(Cask::Config.global.appdir.join("MyFancyApp.app")).not_to exist
+    expect(cask.config.appdir.join("MyFancyApp.app")).not_to exist
   end
 
   it "can uninstall Casks when the uninstall script is missing, but only when using `--force`" do
@@ -79,7 +79,7 @@ describe Cask::Cmd::Uninstall, :cask do
 
     expect(cask).to be_installed
 
-    Cask::Config.global.appdir.join("MyFancyApp.app").rmtree
+    cask.config.appdir.join("MyFancyApp.app").rmtree
 
     expect { described_class.run("with-uninstall-script-app") }
     .to raise_error(Cask::CaskError, /uninstall script .* does not exist/)
diff --git a/Library/Homebrew/test/cask/cmd/upgrade_spec.rb b/Library/Homebrew/test/cask/cmd/upgrade_spec.rb
index b43bb6c9fa..16b2b82049 100644
--- a/Library/Homebrew/test/cask/cmd/upgrade_spec.rb
+++ b/Library/Homebrew/test/cask/cmd/upgrade_spec.rb
@@ -147,7 +147,7 @@ describe Cask::Cmd::Upgrade, :cask do
 
       it 'does not include the Casks with "auto_updates true" when the version did not change' do
         cask = Cask::CaskLoader.load("auto-updates")
-        cask_path = Cask::Config.global.appdir.join("MyFancyApp.app")
+        cask_path = cask.config.appdir.join("MyFancyApp.app")
 
         expect(cask).to be_installed
         expect(cask_path).to be_a_directory
@@ -188,7 +188,7 @@ describe Cask::Cmd::Upgrade, :cask do
 
     it "restores the old Cask if the upgrade failed" do
       will_fail_if_upgraded = Cask::CaskLoader.load("will-fail-if-upgraded")
-      will_fail_if_upgraded_path = Cask::Config.global.appdir.join("container")
+      will_fail_if_upgraded_path = will_fail_if_upgraded.config.appdir.join("container")
 
       expect(will_fail_if_upgraded).to be_installed
       expect(will_fail_if_upgraded_path).to be_a_file
@@ -206,7 +206,7 @@ describe Cask::Cmd::Upgrade, :cask do
 
     it "does not restore the old Cask if the upgrade failed pre-install" do
       bad_checksum = Cask::CaskLoader.load("bad-checksum")
-      bad_checksum_path = Cask::Config.global.appdir.join("Caffeine.app")
+      bad_checksum_path = bad_checksum.config.appdir.join("Caffeine.app")
 
       expect(bad_checksum).to be_installed
       expect(bad_checksum_path).to be_a_directory
diff --git a/Library/Homebrew/test/cask/cmd/zap_spec.rb b/Library/Homebrew/test/cask/cmd/zap_spec.rb
index f7071e0e1a..fd646477e8 100644
--- a/Library/Homebrew/test/cask/cmd/zap_spec.rb
+++ b/Library/Homebrew/test/cask/cmd/zap_spec.rb
@@ -23,8 +23,8 @@ describe Cask::Cmd::Zap, :cask do
     described_class.run("local-caffeine", "local-transmission")
 
     expect(caffeine).not_to be_installed
-    expect(Cask::Config.global.appdir.join("Caffeine.app")).not_to be_a_symlink
+    expect(caffeine.config.appdir.join("Caffeine.app")).not_to be_a_symlink
     expect(transmission).not_to be_installed
-    expect(Cask::Config.global.appdir.join("Transmission.app")).not_to be_a_symlink
+    expect(transmission.config.appdir.join("Transmission.app")).not_to be_a_symlink
   end
 end
diff --git a/Library/Homebrew/test/cask/dsl_spec.rb b/Library/Homebrew/test/cask/dsl_spec.rb
index 0532907f08..d26f237e27 100644
--- a/Library/Homebrew/test/cask/dsl_spec.rb
+++ b/Library/Homebrew/test/cask/dsl_spec.rb
@@ -468,7 +468,7 @@ describe Cask::DSL, :cask do
       let(:token) { "appdir-interpolation" }
 
       it "is allowed" do
-        expect(cask.artifacts.first.source).to eq(Cask::Config.global.appdir/"some/path")
+        expect(cask.artifacts.first.source).to eq(cask.config.appdir/"some/path")
       end
     end
 
diff --git a/Library/Homebrew/test/cask/installer_spec.rb b/Library/Homebrew/test/cask/installer_spec.rb
index ac19ed13bd..b9fbbf9171 100644
--- a/Library/Homebrew/test/cask/installer_spec.rb
+++ b/Library/Homebrew/test/cask/installer_spec.rb
@@ -10,7 +10,7 @@ describe Cask::Installer, :cask do
       Cask::Installer.new(caffeine).install
 
       expect(Cask::Caskroom.path.join("local-caffeine", caffeine.version)).to be_a_directory
-      expect(Cask::Config.global.appdir.join("Caffeine.app")).to be_a_directory
+      expect(caffeine.config.appdir.join("Caffeine.app")).to be_a_directory
     end
 
     it "works with dmg-based Casks" do
@@ -19,7 +19,7 @@ describe Cask::Installer, :cask do
       Cask::Installer.new(asset).install
 
       expect(Cask::Caskroom.path.join("container-dmg", asset.version)).to be_a_directory
-      expect(Cask::Config.global.appdir.join("container")).to be_a_file
+      expect(asset.config.appdir.join("container")).to be_a_file
     end
 
     it "works with tar-gz-based Casks" do
@@ -28,7 +28,7 @@ describe Cask::Installer, :cask do
       Cask::Installer.new(asset).install
 
       expect(Cask::Caskroom.path.join("container-tar-gz", asset.version)).to be_a_directory
-      expect(Cask::Config.global.appdir.join("container")).to be_a_file
+      expect(asset.config.appdir.join("container")).to be_a_file
     end
 
     it "works with xar-based Casks" do
@@ -37,7 +37,7 @@ describe Cask::Installer, :cask do
       Cask::Installer.new(asset).install
 
       expect(Cask::Caskroom.path.join("container-xar", asset.version)).to be_a_directory
-      expect(Cask::Config.global.appdir.join("container")).to be_a_file
+      expect(asset.config.appdir.join("container")).to be_a_file
     end
 
     it "works with pure bzip2-based Casks" do
@@ -46,7 +46,7 @@ describe Cask::Installer, :cask do
       Cask::Installer.new(asset).install
 
       expect(Cask::Caskroom.path.join("container-bzip2", asset.version)).to be_a_directory
-      expect(Cask::Config.global.appdir.join("container")).to be_a_file
+      expect(asset.config.appdir.join("container")).to be_a_file
     end
 
     it "works with pure gzip-based Casks" do
@@ -55,7 +55,7 @@ describe Cask::Installer, :cask do
       Cask::Installer.new(asset).install
 
       expect(Cask::Caskroom.path.join("container-gzip", asset.version)).to be_a_directory
-      expect(Cask::Config.global.appdir.join("container")).to be_a_file
+      expect(asset.config.appdir.join("container")).to be_a_file
     end
 
     it "blows up on a bad checksum" do
diff --git a/Library/Homebrew/test/cask/quarantine_spec.rb b/Library/Homebrew/test/cask/quarantine_spec.rb
index b56818e228..c46706b00b 100644
--- a/Library/Homebrew/test/cask/quarantine_spec.rb
+++ b/Library/Homebrew/test/cask/quarantine_spec.rb
@@ -11,13 +11,11 @@ describe Cask::Quarantine, :cask do
     it "quarantines a nice fresh Cask" do
       Cask::Cmd::Install.run("local-transmission")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("local-transmission")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("local-transmission"))
 
-      expect(
-        Cask::Config.global.appdir.join("Transmission.app"),
-      ).to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("Transmission.app")).to be_quarantined
     end
 
     it "quarantines Cask fetches" do
@@ -42,83 +40,81 @@ describe Cask::Quarantine, :cask do
 
       Cask::Cmd::Install.run("local-transmission")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("local-transmission")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("local-transmission"))
 
-      expect(Cask::Config.global.appdir.join("Transmission.app")).to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("Transmission.app")).to be_quarantined
     end
 
     it "quarantines dmg-based Casks" do
       Cask::Cmd::Install.run("container-dmg")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("container-dmg")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("container-dmg"))
 
-      expect(Cask::Config.global.appdir.join("container")).to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("container")).to be_quarantined
     end
 
     it "quarantines tar-gz-based Casks" do
       Cask::Cmd::Install.run("container-tar-gz")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("container-tar-gz")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("container-tar-gz"))
 
-      expect(Cask::Config.global.appdir.join("container")).to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("container")).to be_quarantined
     end
 
     it "quarantines xar-based Casks" do
       Cask::Cmd::Install.run("container-xar")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("container-xar")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("container-xar"))
 
-      expect(Cask::Config.global.appdir.join("container")).to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("container")).to be_quarantined
     end
 
     it "quarantines pure bzip2-based Casks" do
       Cask::Cmd::Install.run("container-bzip2")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("container-bzip2")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("container-bzip2"))
 
-      expect(Cask::Config.global.appdir.join("container")).to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("container")).to be_quarantined
     end
 
     it "quarantines pure gzip-based Casks" do
       Cask::Cmd::Install.run("container-gzip")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("container-gzip")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("container-gzip"))
 
-      expect(Cask::Config.global.appdir.join("container")).to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("container")).to be_quarantined
     end
 
     it "quarantines the pkg in naked-pkg-based Casks" do
       Cask::Cmd::Install.run("container-pkg")
 
-      naked_pkg = Cask::CaskLoader.load(cask_path("container-pkg"))
+      cask = Cask::CaskLoader.load(cask_path("container-pkg"))
 
-      expect(naked_pkg).to be_installed
+      expect(cask).to be_installed
 
-      expect(
-        Cask::Caskroom.path.join("container-pkg", naked_pkg.version, "container.pkg"),
-      ).to be_quarantined
+      expect(cask.staged_path/"container.pkg").to be_quarantined
     end
 
     it "quarantines a nested container" do
       Cask::Cmd::Install.run("nested-app")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("nested-app")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("nested-app"))
 
-      expect(Cask::Config.global.appdir.join("MyNestedApp.app")).to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("MyNestedApp.app")).to be_quarantined
     end
   end
 
@@ -126,11 +122,11 @@ describe Cask::Quarantine, :cask do
     it "does not quarantine even a nice, fresh Cask" do
       Cask::Cmd::Install.run("local-transmission", "--no-quarantine")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("local-transmission")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("local-transmission"))
 
-      expect(Cask::Config.global.appdir.join("Transmission.app")).not_to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("Transmission.app")).not_to be_quarantined
     end
 
     it "does not quarantine Cask fetches" do
@@ -155,61 +151,61 @@ describe Cask::Quarantine, :cask do
 
       Cask::Cmd::Install.run("local-transmission", "--no-quarantine")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("local-transmission")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("local-transmission"))
 
-      expect(Cask::Config.global.appdir.join("Transmission.app")).not_to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("Transmission.app")).not_to be_quarantined
     end
 
     it "does not quarantine dmg-based Casks" do
       Cask::Cmd::Install.run("container-dmg", "--no-quarantine")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("container-dmg")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("container-dmg"))
 
-      expect(Cask::Config.global.appdir.join("container")).not_to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("container")).not_to be_quarantined
     end
 
     it "does not quarantine tar-gz-based Casks" do
       Cask::Cmd::Install.run("container-tar-gz", "--no-quarantine")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("container-tar-gz")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("container-tar-gz"))
 
-      expect(Cask::Config.global.appdir.join("container")).not_to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("container")).not_to be_quarantined
     end
 
     it "does not quarantine xar-based Casks" do
       Cask::Cmd::Install.run("container-xar", "--no-quarantine")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("container-xar")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("container-xar"))
 
-      expect(Cask::Config.global.appdir.join("container")).not_to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("container")).not_to be_quarantined
     end
 
     it "does not quarantine pure bzip2-based Casks" do
       Cask::Cmd::Install.run("container-bzip2", "--no-quarantine")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("container-bzip2")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("container-bzip2"))
 
-      expect(Cask::Config.global.appdir.join("container")).not_to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("container")).not_to be_quarantined
     end
 
     it "does not quarantine pure gzip-based Casks" do
       Cask::Cmd::Install.run("container-gzip", "--no-quarantine")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("container-gzip")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("container-gzip"))
 
-      expect(Cask::Config.global.appdir.join("container")).not_to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("container")).not_to be_quarantined
     end
 
     it "does not quarantine the pkg in naked-pkg-based Casks" do
@@ -227,11 +223,11 @@ describe Cask::Quarantine, :cask do
     it "does not quarantine a nested container" do
       Cask::Cmd::Install.run("nested-app", "--no-quarantine")
 
-      expect(
-        Cask::CaskLoader.load(cask_path("nested-app")),
-      ).to be_installed
+      cask = Cask::CaskLoader.load(cask_path("nested-app"))
 
-      expect(Cask::Config.global.appdir.join("MyNestedApp.app")).not_to be_quarantined
+      expect(cask).to be_installed
+
+      expect(cask.config.appdir.join("MyNestedApp.app")).not_to be_quarantined
     end
   end
 end
diff --git a/Library/Homebrew/test/support/helper/spec/shared_context/homebrew_cask.rb b/Library/Homebrew/test/support/helper/spec/shared_context/homebrew_cask.rb
index f4432f5f06..bb228b66b4 100644
--- a/Library/Homebrew/test/support/helper/spec/shared_context/homebrew_cask.rb
+++ b/Library/Homebrew/test/support/helper/spec/shared_context/homebrew_cask.rb
@@ -14,7 +14,7 @@ HOMEBREW_CASK_DIRS = {
 RSpec.shared_context "Homebrew Cask", :needs_macos do
   before do
     HOMEBREW_CASK_DIRS.each do |method, path|
-      allow(Cask::Config.global).to receive(method).and_return(path)
+      Cask::Config.global.send("#{method}=", path)
     end
   end