diff --git a/Library/Homebrew/cask/lib/hbc/artifact/nested_container.rb b/Library/Homebrew/cask/lib/hbc/artifact/nested_container.rb
index 801fdfdf74..ca669267f5 100644
--- a/Library/Homebrew/cask/lib/hbc/artifact/nested_container.rb
+++ b/Library/Homebrew/cask/lib/hbc/artifact/nested_container.rb
@@ -28,7 +28,7 @@ module Hbc
         end
 
         ohai "Extracting nested container #{path.relative_path_from(cask.staged_path)}"
-        container.new(cask, path, command, verbose: verbose).extract
+        container.new(cask, path, command, verbose: verbose).extract(to: cask.staged_path)
         FileUtils.remove_entry_secure(path)
       end
     end
diff --git a/Library/Homebrew/cask/lib/hbc/container/air.rb b/Library/Homebrew/cask/lib/hbc/container/air.rb
index d4bafc1b80..6b3ac97923 100644
--- a/Library/Homebrew/cask/lib/hbc/container/air.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/air.rb
@@ -7,9 +7,7 @@ module Hbc
         path.extname == ".air"
       end
 
-      def extract
-        unpack_dir = @cask.staged_path
-
+      def extract_to_dir(unpack_dir, basename:)
         @command.run!(
           "/Applications/Utilities/Adobe AIR Application Installer.app/Contents/MacOS/Adobe AIR Application Installer",
           args: ["-silent", "-location", unpack_dir, path],
diff --git a/Library/Homebrew/cask/lib/hbc/container/base.rb b/Library/Homebrew/cask/lib/hbc/container/base.rb
index ab81173bfa..9e9d595a97 100644
--- a/Library/Homebrew/cask/lib/hbc/container/base.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/base.rb
@@ -1,21 +1,27 @@
 module Hbc
   class Container
     class Base
+      extend Predicable
+
       attr_reader :path
 
+      attr_predicate :verbose?
+
       def initialize(cask, path, command, nested: false, verbose: false)
         @cask = cask
         @path = path
         @command = command
-        @nested = nested
         @verbose = verbose
       end
 
-      def verbose?
-        @verbose
+      def extract(to: nil, basename: nil)
+        basename ||= path.basename
+        unpack_dir = Pathname(to || Dir.pwd).expand_path
+        unpack_dir.mkpath
+        extract_to_dir(unpack_dir, basename: basename)
       end
 
-      def extract_nested_inside(dir)
+      def extract_nested_inside(dir, to:)
         children = Pathname.new(dir).children
 
         nested_container = children[0]
@@ -23,7 +29,7 @@ module Hbc
         unless children.count == 1 &&
                !nested_container.directory? &&
                @cask.artifacts.none? { |a| a.is_a?(Artifact::NestedContainer) } &&
-               extract_nested_container(nested_container)
+               extract_nested_container(nested_container, to: to)
 
           children.each do |src|
             dest = @cask.staged_path.join(src.basename)
@@ -33,13 +39,13 @@ module Hbc
         end
       end
 
-      def extract_nested_container(source)
+      def extract_nested_container(source, to:)
         container = Container.for_path(source)
 
         return false unless container
 
         ohai "Extracting nested container #{source.basename}"
-        container.new(@cask, source, @command, nested: true, verbose: verbose?).extract
+        container.new(@cask, source, @command, verbose: verbose?).extract(to: to)
 
         true
       end
diff --git a/Library/Homebrew/cask/lib/hbc/container/bzip2.rb b/Library/Homebrew/cask/lib/hbc/container/bzip2.rb
index e9746d6772..78c4f096fb 100644
--- a/Library/Homebrew/cask/lib/hbc/container/bzip2.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/bzip2.rb
@@ -7,12 +7,14 @@ module Hbc
         magic_number.match?(/\ABZh/n)
       end
 
-      def extract
-        Dir.mktmpdir do |unpack_dir|
-          @command.run!("/usr/bin/ditto", args: ["--", @path, unpack_dir])
-          @command.run!("bunzip2", args: ["--quiet", "--", Pathname.new(unpack_dir).join(@path.basename)])
+      def extract_to_dir(unpack_dir, basename:)
+        Dir.mktmpdir do |tmp_unpack_dir|
+          tmp_unpack_dir = Pathname(tmp_unpack_dir)
 
-          extract_nested_inside(unpack_dir)
+          FileUtils.cp path, tmp_unpack_dir/basename, preserve: true
+          @command.run!("bunzip2", args: ["--quiet", "--", tmp_unpack_dir/basename])
+
+          extract_nested_inside(tmp_unpack_dir, to: unpack_dir)
         end
       end
     end
diff --git a/Library/Homebrew/cask/lib/hbc/container/cab.rb b/Library/Homebrew/cask/lib/hbc/container/cab.rb
index 2615e8e680..28c4a0c665 100644
--- a/Library/Homebrew/cask/lib/hbc/container/cab.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/cab.rb
@@ -7,13 +7,10 @@ module Hbc
         magic_number.match?(/\A(MSCF|MZ)/n)
       end
 
-      def extract
-        Dir.mktmpdir do |unpack_dir|
-          @command.run!("cabextract",
-                        args: ["-d", unpack_dir, "--", @path],
-                        env: { "PATH" => PATH.new(Formula["cabextract"].opt_bin, ENV["PATH"]) })
-          @command.run!("/usr/bin/ditto", args: ["--", unpack_dir, @cask.staged_path])
-        end
+      def extract_to_dir(unpack_dir, basename:)
+        @command.run!("cabextract",
+                      args: ["-d", unpack_dir, "--", path],
+                      env: { "PATH" => PATH.new(Formula["cabextract"].opt_bin, ENV["PATH"]) })
       end
 
       def dependencies
diff --git a/Library/Homebrew/cask/lib/hbc/container/dmg.rb b/Library/Homebrew/cask/lib/hbc/container/dmg.rb
index bd3e9103a8..a3ca9754e3 100644
--- a/Library/Homebrew/cask/lib/hbc/container/dmg.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/dmg.rb
@@ -14,11 +14,13 @@ module Hbc
         !imageinfo.empty?
       end
 
-      def extract
+      def extract_to_dir(unpack_dir, basename:)
         mount do |mounts|
           begin
             raise CaskError, "No mounts found in '#{@path}'; perhaps it is a bad disk image?" if mounts.empty?
-            mounts.each(&method(:extract_mount))
+            mounts.each do |mount|
+              extract_mount(mount, to: unpack_dir)
+            end
           ensure
             mounts.each(&method(:eject))
           end
@@ -84,7 +86,7 @@ module Hbc
 
       private
 
-      def extract_mount(mount)
+      def extract_mount(mount, to:)
         Tempfile.open(["", ".bom"]) do |bomfile|
           bomfile.close
 
@@ -93,7 +95,7 @@ module Hbc
             filelist.close
 
             @command.run!("/usr/bin/mkbom", args: ["-s", "-i", filelist.path, "--", bomfile.path])
-            @command.run!("/usr/bin/ditto", args: ["--bom", bomfile.path, "--", mount, @cask.staged_path])
+            @command.run!("/usr/bin/ditto", args: ["--bom", bomfile.path, "--", mount, to])
           end
         end
       end
diff --git a/Library/Homebrew/cask/lib/hbc/container/generic_unar.rb b/Library/Homebrew/cask/lib/hbc/container/generic_unar.rb
index bfd1c53729..0b3f2f8ea5 100644
--- a/Library/Homebrew/cask/lib/hbc/container/generic_unar.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/generic_unar.rb
@@ -7,9 +7,7 @@ module Hbc
         false
       end
 
-      def extract
-        unpack_dir = @cask.staged_path
-
+      def extract_to_dir(unpack_dir, basename:)
         @command.run!("unar",
                       args: ["-force-overwrite", "-quiet", "-no-directory", "-output-directory", unpack_dir, "--", path],
                       env: { "PATH" => PATH.new(Formula["unar"].opt_bin, ENV["PATH"]) })
diff --git a/Library/Homebrew/cask/lib/hbc/container/gpg.rb b/Library/Homebrew/cask/lib/hbc/container/gpg.rb
index fc39488ea8..10ca691338 100644
--- a/Library/Homebrew/cask/lib/hbc/container/gpg.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/gpg.rb
@@ -23,15 +23,15 @@ module Hbc
                       env: { "PATH" => PATH.new(Formula["gnupg"].opt_bin, ENV["PATH"]) })
       end
 
-      def extract
+      def extract_to_dir(unpack_dir, basename:)
         import_key
 
-        Dir.mktmpdir do |unpack_dir|
+        Dir.mktmpdir do |tmp_unpack_dir|
           @command.run!("gpg",
-                        args: ["--batch", "--yes", "--output", Pathname(unpack_dir).join(@path.basename(".gpg")), "--decrypt", @path],
+                        args: ["--batch", "--yes", "--output", Pathname(tmp_unpack_dir).join(basename.basename(".gpg")), "--decrypt", path],
                         env: { "PATH" => PATH.new(Formula["gnupg"].opt_bin, ENV["PATH"]) })
 
-          extract_nested_inside(unpack_dir)
+          extract_nested_inside(tmp_unpack_dir, to: unpack_dir)
         end
       end
 
diff --git a/Library/Homebrew/cask/lib/hbc/container/gzip.rb b/Library/Homebrew/cask/lib/hbc/container/gzip.rb
index 7263f91f8a..bc67c64bb5 100644
--- a/Library/Homebrew/cask/lib/hbc/container/gzip.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/gzip.rb
@@ -7,12 +7,14 @@ module Hbc
         magic_number.match?(/\A\037\213/n)
       end
 
-      def extract
-        Dir.mktmpdir do |unpack_dir|
-          @command.run!("/usr/bin/ditto", args: ["--", @path, unpack_dir])
-          @command.run!("gunzip", args: ["--quiet", "--name", "--", Pathname.new(unpack_dir).join(@path.basename)])
+      def extract_to_dir(unpack_dir, basename:)
+        Dir.mktmpdir do |tmp_unpack_dir|
+          tmp_unpack_dir = Pathname(tmp_unpack_dir)
 
-          extract_nested_inside(unpack_dir)
+          FileUtils.cp path, tmp_unpack_dir/basename, preserve: true
+          @command.run!("gunzip", args: ["--quiet", "--name", "--", tmp_unpack_dir/basename])
+
+          extract_nested_inside(tmp_unpack_dir, to: unpack_dir)
         end
       end
     end
diff --git a/Library/Homebrew/cask/lib/hbc/container/lzma.rb b/Library/Homebrew/cask/lib/hbc/container/lzma.rb
index a1980e903a..79be731bf4 100644
--- a/Library/Homebrew/cask/lib/hbc/container/lzma.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/lzma.rb
@@ -7,14 +7,11 @@ module Hbc
         magic_number.match?(/\A\]\000\000\200\000/n)
       end
 
-      def extract
-        Dir.mktmpdir do |unpack_dir|
-          @command.run!("/usr/bin/ditto", args: ["--", @path, unpack_dir])
-          @command.run!("unlzma",
-                        args: ["-q", "--", Pathname(unpack_dir).join(@path.basename)],
-                        env: { "PATH" => PATH.new(Formula["unlzma"].opt_bin, ENV["PATH"]) })
-          @command.run!("/usr/bin/ditto", args: ["--", unpack_dir, @cask.staged_path])
-        end
+      def extract_to_dir(unpack_dir, basename:)
+        @command.run!("/usr/bin/ditto", args: ["--", path, unpack_dir])
+        @command.run!("unlzma",
+                      args: ["-q", "--", Pathname(unpack_dir).join(basename)],
+                      env: { "PATH" => PATH.new(Formula["unlzma"].opt_bin, ENV["PATH"]) })
       end
 
       def dependencies
diff --git a/Library/Homebrew/cask/lib/hbc/container/naked.rb b/Library/Homebrew/cask/lib/hbc/container/naked.rb
index 7ba94f8040..4b32a222b5 100644
--- a/Library/Homebrew/cask/lib/hbc/container/naked.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/naked.rb
@@ -7,13 +7,8 @@ module Hbc
         false
       end
 
-      def extract
-        @command.run!("/usr/bin/ditto", args: ["--", @path, @cask.staged_path.join(target_file)])
-      end
-
-      def target_file
-        return @path.basename if @nested
-        CGI.unescape(File.basename(@cask.url.path))
+      def extract_to_dir(unpack_dir, basename:)
+        @command.run!("/usr/bin/ditto", args: ["--", path, unpack_dir/basename])
       end
     end
   end
diff --git a/Library/Homebrew/cask/lib/hbc/container/rar.rb b/Library/Homebrew/cask/lib/hbc/container/rar.rb
index 1ad334202a..b060fc515c 100644
--- a/Library/Homebrew/cask/lib/hbc/container/rar.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/rar.rb
@@ -7,10 +7,10 @@ module Hbc
         magic_number.match?(/\ARar!/n)
       end
 
-      def extract
-        path = @path
-        unpack_dir = @cask.staged_path
-        @command.run!(Formula["unrar"].opt_bin/"unrar", args: ["x", "-inul", path, unpack_dir])
+      def extract_to_dir(unpack_dir, basename:)
+        @command.run!("unrar",
+                      args: ["x", "-inul", path, unpack_dir],
+                      env: { "PATH" => PATH.new(Formula["unrar"].opt_bin, ENV["PATH"]) })
       end
 
       def dependencies
diff --git a/Library/Homebrew/cask/lib/hbc/container/seven_zip.rb b/Library/Homebrew/cask/lib/hbc/container/seven_zip.rb
index 33612fb9c0..76ab0590ee 100644
--- a/Library/Homebrew/cask/lib/hbc/container/seven_zip.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/seven_zip.rb
@@ -7,9 +7,7 @@ module Hbc
         magic_number.match?(/\A7z\xBC\xAF\x27\x1C/n)
       end
 
-      def extract
-        unpack_dir = @cask.staged_path
-
+      def extract_to_dir(unpack_dir, basename:)
         @command.run!("7zr",
                       args: ["x", "-y", "-bd", "-bso0", path, "-o#{unpack_dir}"],
                       env: { "PATH" => PATH.new(Formula["p7zip"].opt_bin, ENV["PATH"]) })
diff --git a/Library/Homebrew/cask/lib/hbc/container/svn_repository.rb b/Library/Homebrew/cask/lib/hbc/container/svn_repository.rb
index fd49857fd8..eaa5a8f213 100644
--- a/Library/Homebrew/cask/lib/hbc/container/svn_repository.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/svn_repository.rb
@@ -5,10 +5,7 @@ module Hbc
         (path/".svn").directory?
       end
 
-      def extract
-        path = @path
-        unpack_dir = @cask.staged_path
-
+      def extract_to_dir(unpack_dir, basename:)
         @command.run!("svn", args: ["export", "--force", path, unpack_dir])
       end
     end
diff --git a/Library/Homebrew/cask/lib/hbc/container/tar.rb b/Library/Homebrew/cask/lib/hbc/container/tar.rb
index 3cdbcb226d..5f7f401458 100644
--- a/Library/Homebrew/cask/lib/hbc/container/tar.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/tar.rb
@@ -12,9 +12,7 @@ module Hbc
         end
       end
 
-      def extract
-        unpack_dir = @cask.staged_path
-
+      def extract_to_dir(unpack_dir, basename:)
         @command.run!("tar", args: ["xf", path, "-C", unpack_dir])
       end
     end
diff --git a/Library/Homebrew/cask/lib/hbc/container/xar.rb b/Library/Homebrew/cask/lib/hbc/container/xar.rb
index 0e665b64a0..7b653a787c 100644
--- a/Library/Homebrew/cask/lib/hbc/container/xar.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/xar.rb
@@ -7,9 +7,7 @@ module Hbc
         magic_number.match?(/\Axar!/n)
       end
 
-      def extract
-        unpack_dir = @cask.staged_path
-
+      def extract_to_dir(unpack_dir, basename:)
         @command.run!("xar", args: ["-x", "-f", @path, "-C", unpack_dir])
       end
     end
diff --git a/Library/Homebrew/cask/lib/hbc/container/xz.rb b/Library/Homebrew/cask/lib/hbc/container/xz.rb
index 5980e84d58..043bf50152 100644
--- a/Library/Homebrew/cask/lib/hbc/container/xz.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/xz.rb
@@ -7,12 +7,9 @@ module Hbc
         magic_number.match?(/\A\xFD7zXZ\x00/n)
       end
 
-      def extract
-        unpack_dir = @cask.staged_path
-        basename = path.basename
-
+      def extract_to_dir(unpack_dir, basename:)
         @command.run!("/usr/bin/ditto", args: ["--", path, unpack_dir])
-        @command.run!("xz",
+        @command.run!("unxz",
                       args: ["-q", "--", unpack_dir/basename],
                       env: { "PATH" => PATH.new(Formula["xz"].opt_bin, ENV["PATH"]) })
       end
diff --git a/Library/Homebrew/cask/lib/hbc/container/zip.rb b/Library/Homebrew/cask/lib/hbc/container/zip.rb
index aee5485ffe..390ee48421 100644
--- a/Library/Homebrew/cask/lib/hbc/container/zip.rb
+++ b/Library/Homebrew/cask/lib/hbc/container/zip.rb
@@ -7,11 +7,11 @@ module Hbc
         magic_number.match?(/\APK(\003\004|\005\006)/n)
       end
 
-      def extract
-        Dir.mktmpdir do |unpack_dir|
-          @command.run!("/usr/bin/ditto", args: ["-x", "-k", "--", @path, unpack_dir])
+      def extract_to_dir(unpack_dir, basename:)
+        Dir.mktmpdir do |tmp_unpack_dir|
+          @command.run!("/usr/bin/ditto", args: ["-x", "-k", "--", path, tmp_unpack_dir])
 
-          extract_nested_inside(unpack_dir)
+          extract_nested_inside(tmp_unpack_dir, to: unpack_dir)
         end
       end
     end
diff --git a/Library/Homebrew/cask/lib/hbc/installer.rb b/Library/Homebrew/cask/lib/hbc/installer.rb
index 47bb770261..64d2d01274 100644
--- a/Library/Homebrew/cask/lib/hbc/installer.rb
+++ b/Library/Homebrew/cask/lib/hbc/installer.rb
@@ -6,6 +6,8 @@ require "hbc/cask_dependencies"
 require "hbc/staged"
 require "hbc/verify"
 
+require "cgi"
+
 module Hbc
   class Installer
     extend Predicable
@@ -164,8 +166,9 @@ module Hbc
       end
 
       odebug "Using container class #{primary_container.class} for #{@downloaded_path}"
-      FileUtils.mkdir_p @cask.staged_path
-      primary_container.extract
+
+      basename = CGI.unescape(File.basename(@cask.url.path))
+      primary_container.extract(to: @cask.staged_path, basename: basename)
     end
 
     def install_artifacts
diff --git a/Library/Homebrew/test/cask/container/naked_spec.rb b/Library/Homebrew/test/cask/container/naked_spec.rb
index 1167a9cc10..f147b06b9d 100644
--- a/Library/Homebrew/test/cask/container/naked_spec.rb
+++ b/Library/Homebrew/test/cask/container/naked_spec.rb
@@ -5,7 +5,7 @@ describe Hbc::Container::Naked, :cask do
       version "1.2"
     end
 
-    path                 = "/tmp/downloads/kevin-spacey-1.2.pkg"
+    path                 = Pathname("/tmp/downloads/kevin-spacey.pkg")
     expected_destination = cask.staged_path.join("kevin spacey.pkg")
 
     container = Hbc::Container::Naked.new(cask, path, Hbc::FakeSystemCommand)
@@ -15,7 +15,7 @@ describe Hbc::Container::Naked, :cask do
     )
 
     expect {
-      container.extract
+      container.extract(to: cask.staged_path, basename: "kevin spacey.pkg")
     }.not_to raise_error
   end
 end
diff --git a/Library/Homebrew/test/cask/installer_spec.rb b/Library/Homebrew/test/cask/installer_spec.rb
index f966176546..ab25dde2a3 100644
--- a/Library/Homebrew/test/cask/installer_spec.rb
+++ b/Library/Homebrew/test/cask/installer_spec.rb
@@ -46,7 +46,7 @@ describe Hbc::Installer, :cask do
       Hbc::Installer.new(asset).install
 
       expect(Hbc::Caskroom.path.join("container-bzip2", asset.version)).to be_a_directory
-      expect(Hbc::Config.global.appdir.join("container-bzip2--#{asset.version}")).to be_a_file
+      expect(Hbc::Config.global.appdir.join("container")).to be_a_file
     end
 
     it "works with pure gzip-based Casks" do
diff --git a/Library/Homebrew/test/support/fixtures/cask/Casks/container-bzip2.rb b/Library/Homebrew/test/support/fixtures/cask/Casks/container-bzip2.rb
index 60f834b7f3..8d0d76e1b7 100644
--- a/Library/Homebrew/test/support/fixtures/cask/Casks/container-bzip2.rb
+++ b/Library/Homebrew/test/support/fixtures/cask/Casks/container-bzip2.rb
@@ -5,5 +5,5 @@ cask 'container-bzip2' do
   url "file://#{TEST_FIXTURE_DIR}/cask/container.bz2"
   homepage 'https://example.com/container-bzip2'
 
-  app 'container-bzip2--1.2.3'
+  app 'container'
 end