diff --git a/lib/paperclip.rb b/lib/paperclip.rb
index 57b9712f4..3a22429ce 100644
--- a/lib/paperclip.rb
+++ b/lib/paperclip.rb
@@ -120,8 +120,6 @@ def included base #:nodoc:
       base.extend ClassMethods
       if base.respond_to?("set_callback")
         base.send :include, Paperclip::CallbackCompatability::Rails3
-      elsif !base.respond_to?("define_callbacks")
-        base.send :include, Paperclip::CallbackCompatability::Rails20
       else
         base.send :include, Paperclip::CallbackCompatability::Rails21
       end