diff --git a/Rakefile b/Rakefile
index 6527a82f..5ee3b515 100644
--- a/Rakefile
+++ b/Rakefile
@@ -26,6 +26,8 @@ end
 namespace :benchmark do
   require 'git'
   require 'linguist/language'
+  require 'linguist/diff'
+  require 'json'
 
   git = Git.open('.')
 
@@ -65,6 +67,11 @@ namespace :benchmark do
     git.branch("tmp_#{compare}").delete
 
     # DO COMPARISON...
+    reference_classifications = JSON.parse(File.read("benchmark/results/#{reference}_output.json"))
+
+    compare_classifications = JSON.parse(File.read("benchmark/results/#{compare}_output.json"))
+
+    puts reference_classifications.deep_diff(compare_classifications)
   end
 
   desc "Build benchmark index"
@@ -73,9 +80,11 @@ namespace :benchmark do
     languages = Dir.glob('benchmark/samples/*')
 
     languages.each do |lang|
+      puts "Starting with #{lang}"
       results[lang] = {}
       files = Dir.glob("#{lang}/*")
       files.each do |file|
+        puts file
         result = IO::popen("bundle exec linguist #{file} --simple").read
         filename = File.basename(file)
         if result.chomp.empty? # No results
diff --git a/lib/linguist/diff.rb b/lib/linguist/diff.rb
new file mode 100644
index 00000000..0cf75182
--- /dev/null
+++ b/lib/linguist/diff.rb
@@ -0,0 +1,15 @@
+class Hash
+  def deep_diff(b)
+    a = self
+    (a.keys | b.keys).inject({}) do |diff, k|
+      if a[k] != b[k]
+        if a[k].respond_to?(:deep_diff) && b[k].respond_to?(:deep_diff)
+          diff[k] = a[k].deep_diff(b[k])
+        else
+          diff[k] = [a[k], b[k]]
+        end
+      end
+      diff
+    end
+  end
+end