diff --git a/lib/cask.rb b/lib/cask.rb
index af41fc5b9..55e685a83 100644
--- a/lib/cask.rb
+++ b/lib/cask.rb
@@ -3,9 +3,11 @@ require 'uri'
 class Cask; end
 class Cask::CLI; end
 
-Dir[File.join(File.dirname(__FILE__), '**', '*.rb')].each { |file| 
-  require file.sub(/^lib\/(.*).rb$/, '\1')
-}
+libdir = File.dirname(__FILE__)
+rubyfiles = Dir[File.join(libdir, '**', '*.rb')]
+rubyfiles.each do |file|
+  require file.sub(/^#{libdir}\/(.*).rb$/, '\1')
+end
 
 class Cask
   include Cask::Actions
diff --git a/lib/cask/installer.rb b/lib/cask/installer.rb
index 28a13bf15..6f5325a16 100644
--- a/lib/cask/installer.rb
+++ b/lib/cask/installer.rb
@@ -22,7 +22,6 @@ class Cask::Installer
 
     def _with_extracted_mountpoints(path)
       if _dmg?(path)
-        require 'plist/parser'
         File.open(path) do |dmg|
           xml_str = `hdiutil mount -plist -nobrowse -readonly -noidme -mountrandom /tmp '#{dmg.path}'`
           hdiutil_info = Plist::parse_xml(xml_str)
diff --git a/test/cask/installer_test.rb b/test/cask/installer_test.rb
index 2b98487b4..91260929b 100644
--- a/test/cask/installer_test.rb
+++ b/test/cask/installer_test.rb
@@ -14,6 +14,19 @@ describe Cask::Installer do
       application = dest_path/'Caffeine.app'
       application.must_be :directory?
     end
+
+    it "works with dmg-based casks" do
+      transmission = Cask.load('local-transmission')
+
+      shutup do
+        Cask::Installer.install(transmission)
+      end
+
+      dest_path = HOMEBREW_CELLAR/'local-transmission'/transmission.version
+      dest_path.must_be :directory?
+      application = dest_path/'Transmission.app'
+      application.must_be :directory?
+    end
   end
 
   describe "uninstall" do
diff --git a/test/support/Casks/local-transmission.rb b/test/support/Casks/local-transmission.rb
new file mode 100644
index 000000000..5b2726c18
--- /dev/null
+++ b/test/support/Casks/local-transmission.rb
@@ -0,0 +1,5 @@
+class LocalTransmission < Cask
+  url TestHelper.local_binary('transmission-2.61.dmg')
+  homepage 'http://example.com/local-transmission'
+  version '2.61'
+end
diff --git a/test/support/binaries/transmission-2.61.dmg b/test/support/binaries/transmission-2.61.dmg
new file mode 100644
index 000000000..b9629f837
Binary files /dev/null and b/test/support/binaries/transmission-2.61.dmg differ