diff --git a/plugins/comment_group/test/unit/article_test.rb b/plugins/comment_group/test/unit/article_test.rb
index 15a963f..4448760 100644
--- a/plugins/comment_group/test/unit/article_test.rb
+++ b/plugins/comment_group/test/unit/article_test.rb
@@ -1,4 +1,5 @@
 require File.dirname(__FILE__) + '/../test_helper'
+require 'benchmark'
 
 class ArticleTest < ActiveSupport::TestCase
 
@@ -36,4 +37,20 @@ class ArticleTest < ActiveSupport::TestCase
     assert article.save
   end
 
+  should 'improve performance checking changes in body' do
+    i = 1
+    time0 = (Benchmark.measure { 50.times {
+      i = i + 1
+      article.body = "i = #{i}"
+      assert article.save
+    }})
+    i = 1
+    time1 = (Benchmark.measure { 50.times {
+      i = i + 1
+      article.body = "i = 1"
+      assert article.save
+    }})
+    assert time0.total > time1.total
+  end
+
 end
--
libgit2 0.21.2