diff --git a/app/controllers/public/content_viewer_controller.rb b/app/controllers/public/content_viewer_controller.rb
index b036eb6..001b2ce 100644
--- a/app/controllers/public/content_viewer_controller.rb
+++ b/app/controllers/public/content_viewer_controller.rb
@@ -120,6 +120,10 @@ class ContentViewerController < ApplicationController
     end
   end
 
+  def self.versioning_articles(article1, article2)
+    Diffy::Diff.new('article1', 'article2', :source => 'files').to_s(:html)
+  end
+
   protected
 
   def per_page
@@ -152,8 +156,6 @@ class ContentViewerController < ApplicationController
 
 end
 
-  def versioning_articles(article1, article2)
-    Diffy::Diff.new('article1', 'article2', :source => 'files').to_s(:html)
-  end
+
 
 
diff --git a/test/functional/content_viewer_controller_test.rb b/test/functional/content_viewer_controller_test.rb
index 55a066b..1af7e05 100644
--- a/test/functional/content_viewer_controller_test.rb
+++ b/test/functional/content_viewer_controller_test.rb
@@ -1195,7 +1195,7 @@ class ContentViewerControllerTest < ActionController::TestCase
   end
 
   should 'display differences between article versions' do
-    Article.versioning_articles('/files/test.txt','/files/test.txt')
+    ContentViewerController.versioning_articles('/files/test.txt','/files/test.txt')
   end
 
   should 'not display comments marked as spam' do
--
libgit2 0.21.2