diff --git a/lib/jasmine/headless/files_list.rb b/lib/jasmine/headless/files_list.rb
index 68ef4e4..c7e9241 100644
--- a/lib/jasmine/headless/files_list.rb
+++ b/lib/jasmine/headless/files_list.rb
@@ -20,7 +20,7 @@ module Jasmine::Headless
         Gem::Specification.each do |spec|
           path = File.join(spec.gem_dir, 'vendor/assets/javascripts')
 
-          @vendor_asset_paths << path if File.directory?(path)
+          @vendor_asset_paths << path if File.directory?(path) && !@vendor_asset_paths.include?(path)
         end
 
         @vendor_asset_paths
@@ -68,7 +68,11 @@ module Jasmine::Headless
       @potential_files_to_filter = []
 
       self.class.default_files.each do |file|
-        @required_files << sprockets_environment.find_asset(file, :bundle => false)
+        begin
+          @required_files << sprockets_environment.find_asset(file, :bundle => false)
+        rescue InvalidUniqueAsset => e
+          raise StandardError.new("Not an asset: #{file}")
+        end
       end
 
       use_config! if config?
@@ -91,7 +95,7 @@ module Jasmine::Headless
     def search_paths
       return @search_paths if @search_paths
 
-      @search_paths = [ Jasmine::Core.path ]
+      @search_paths = [ Jasmine::Core.path, Jasmine::Headless.root.join('vendor/assets/javascripts').to_s ]
       @search_paths += self.class.vendor_asset_paths
       @search_paths += src_dir.collect { |dir| File.expand_path(dir) }
       @search_paths += spec_dir.collect { |dir| File.expand_path(dir) }
diff --git a/lib/jasmine/headless/unique_asset_list.rb b/lib/jasmine/headless/unique_asset_list.rb
index 6e27d4e..14ed9f4 100644
--- a/lib/jasmine/headless/unique_asset_list.rb
+++ b/lib/jasmine/headless/unique_asset_list.rb
@@ -1,7 +1,7 @@
 module Jasmine::Headless
   class UniqueAssetList < ::Array
     def <<(asset)
-      raise StandardError.new("Not an asset") if !asset.respond_to?(:logical_path)
+      raise InvalidUniqueAsset.new("Not an asset: #{asset.inspect}") if !asset.respond_to?(:logical_path)
 
       super if !self.any? { |other| asset.logical_path == other.logical_path }
     end
@@ -10,5 +10,7 @@ module Jasmine::Headless
       self.collect(&:to_a).flatten
     end
   end
+
+  class InvalidUniqueAsset < StandardError ; end
 end
 
diff --git a/spec/lib/jasmine/headless/files_list_spec.rb b/spec/lib/jasmine/headless/files_list_spec.rb
index 0a8f9e5..45765e4 100644
--- a/spec/lib/jasmine/headless/files_list_spec.rb
+++ b/spec/lib/jasmine/headless/files_list_spec.rb
@@ -67,9 +67,11 @@ describe Jasmine::Headless::FilesList do
       Jasmine::Headless::FilesList.stubs(:vendor_asset_paths).returns([])
     end
 
+    let(:vendor_path) { Jasmine::Headless.root.join('vendor/assets/javascripts').to_s }
+
     context 'no vendored gem paths' do
       it 'should take the src dir and spec dirs' do
-        files_list.search_paths.should == [ Jasmine::Core.path, File.expand_path(src_dir), File.expand_path(spec_dir) ]
+        files_list.search_paths.should == [ Jasmine::Core.path, vendor_path, File.expand_path(src_dir), File.expand_path(spec_dir) ]
       end
     end
 
@@ -79,7 +81,7 @@ describe Jasmine::Headless::FilesList do
       end
 
       it 'should add the vendor gem paths to the list' do
-        files_list.search_paths.should == [ Jasmine::Core.path, path, File.expand_path(src_dir), File.expand_path(spec_dir) ]
+        files_list.search_paths.should == [ Jasmine::Core.path, vendor_path, path, File.expand_path(src_dir), File.expand_path(spec_dir) ]
       end
     end
 
@@ -90,7 +92,7 @@ describe Jasmine::Headless::FilesList do
       let(:src_dir) { [ dir_1, dir_2 ] }
 
       it 'should take the src dir and spec dirs' do
-        files_list.search_paths.should == [ Jasmine::Core.path, File.expand_path(dir_1), File.expand_path(dir_2), File.expand_path(spec_dir) ]
+        files_list.search_paths.should == [ Jasmine::Core.path, vendor_path, File.expand_path(dir_1), File.expand_path(dir_2), File.expand_path(spec_dir) ]
       end
     end
   end