diff --git a/lib/rake-pipeline-web-filters/neuter_filter.rb b/lib/rake-pipeline-web-filters/neuter_filter.rb
index 8f3bb8e..c57456a 100644
--- a/lib/rake-pipeline-web-filters/neuter_filter.rb
+++ b/lib/rake-pipeline-web-filters/neuter_filter.rb
@@ -49,13 +49,13 @@ def batch(batch)
       @batch.required(fullpath)
     end
 
-    def read
-      source = super
+    def neuter
+      source = read
 
       required_files = @batch.strip_requires(source).map do |req|
         req_path = @batch.transform_path(req, self)
         if req_path && !@batch.required?(File.expand_path(req_path, root))
-          @batch.file_wrapper(self.class, root, req_path, encoding).read
+          @batch.file_wrapper(self.class, root, req_path, encoding).neuter
         else
           nil
         end
@@ -65,6 +65,12 @@ def read
 
       (required_files << file).join("\n\n")
     end
+
+    def dependencies
+      @batch.strip_requires(read).map do |req|
+        req_path = @batch.transform_path(req, self)
+      end
+    end
   end
 
   # A filter that takes files with requires and collapses them into a single
@@ -95,17 +101,15 @@ def generate_output(inputs, output)
         known_files = [input.fullpath] + additional_dependencies(input)
         batch = NeuterBatch.new(@config, known_files)
         file = batch.file_wrapper(file_wrapper_class, input.root, input.path, input.encoding)
-        output.write file.read
+        output.write file.neuter
       end
     end
 
     def additional_dependencies(input)
-      regexp = @config[:require_regexp] || %r{^\s*require\(['"]([^'"]*)['"]\);?\s*}
-      requires = input.read.scan regexp
-
-      requires.flatten.map do |file|
-        @config[:path_transform] ? @config[:path_transform].call(file) : file
-      end
+      return []
+      batch = NeuterBatch.new @config, [input.fullpath]
+      wrapper = batch.file_wrapper(file_wrapper_class, input.root, input.path, input.encoding)
+      wrapper.dependencies
     end
   end
 end
diff --git a/spec/neuter_filter_spec.rb b/spec/neuter_filter_spec.rb
index 25ae42d..2f5abab 100644
--- a/spec/neuter_filter_spec.rb
+++ b/spec/neuter_filter_spec.rb
@@ -175,10 +175,9 @@ def capture(*streams)
     describe "additional_dependencies" do
       let!(:main_input_file) { make_input("a.js", %Q{require("b");}) }
       let!(:required_input_file) { make_input("b.js", "foo") }
-      let!(:path_transform) { proc { |f| "/path/to/input/#{f}.js" } }
 
       it "determines them from require statments in the file" do
-        filter = Rake::Pipeline::Web::Filters::NeuterFilter.new :path_transform => path_transform
+        filter = Rake::Pipeline::Web::Filters::NeuterFilter.new
         filter.input_files = [main_input_file]
         filter.output_root = "/path/to/output"
         filter.rake_application = Rake::Application.new