diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
new file mode 100644
index 0000000..d931441
--- /dev/null
+++ b/spec/spec_helper.rb
@@ -0,0 +1,8 @@
+require 'mocha'
+require 'fakefs/spec_helpers'
+require 'sprockets-vendor_gems'
+
+RSpec.configure do |c|
+  c.mock_with :mocha
+end
+
diff --git a/spec/sprockets-vendor_gems_spec.rb b/spec/sprockets-vendor_gems_spec.rb
new file mode 100644
index 0000000..3d39330
--- /dev/null
+++ b/spec/sprockets-vendor_gems_spec.rb
@@ -0,0 +1,42 @@
+require 'spec_helper'
+
+describe Sprockets do
+  include FakeFS::SpecHelpers
+
+  describe '.find_gem_vendor_paths' do
+    let(:gem_dir) { "dir" }
+    let(:gemspec) { stub(:gem_dir => gem_dir) }
+
+    let(:paths) do
+      %w{vendor lib app}.collect do |dir|
+        File.join(gem_dir, dir, 'assets/javascripts')
+        File.join(gem_dir, dir, 'assets/stylesheets')
+      end
+    end
+
+    before do
+      paths.each { |path| FileUtils.mkdir_p path }
+
+      Gem::Specification.stubs(:each).yields(gemspec)
+    end
+
+    subject { described_class.find_gem_vendor_paths }
+
+    it { should =~ paths }
+  end
+end
+
+describe Sprockets::EnvironmentWithVendoredGems do
+  let(:env) { described_class.new }
+  let(:path) { 'path' }
+
+  before do
+    Sprockets.expects(:find_gem_vendor_paths).returns([ path ])
+
+    described_class.any_instance.expects(:append_path).with(path)
+  end
+
+  it 'should work' do
+    env
+  end
+end
diff --git a/sprockets-vendor_gems.gemspec b/sprockets-vendor_gems.gemspec
index 9c1c0b0..26ab54e 100644
--- a/sprockets-vendor_gems.gemspec
+++ b/sprockets-vendor_gems.gemspec
@@ -14,5 +14,11 @@ Gem::Specification.new do |gem|
   gem.version       = '0.1.1'
 
   gem.required_rubygems_version = '>= 1.8.0'
+
+  gem.add_dependency 'sprockets'
+
+  gem.add_development_dependency 'rspec'
+  gem.add_development_dependency 'mocha'
+  gem.add_development_dependency 'fakefs'
 end