diff --git a/activesupport/lib/dependencies.rb b/activesupport/lib/dependencies.rb
index 3ceec71873..e5e806b65a 100644
--- a/activesupport/lib/dependencies.rb
+++ b/activesupport/lib/dependencies.rb
@@ -35,6 +35,10 @@ module Dependencies
   def require_or_load(file_name)
     load? ? load("#{file_name}.rb") : require(file_name)
   end
+  
+  def remove_subclasses_for(*classes)
+    classes.each { |klass| klass.remove_subclasses }
+  end
 end
 
 Object.send(:define_method, :require_or_load)     { |file_name| Dependencies.require_or_load(file_name) } unless Object.respond_to?(:require_or_load)
diff --git a/railties/lib/dispatcher.rb b/railties/lib/dispatcher.rb
index 84dff75024..566b031295 100644
--- a/railties/lib/dispatcher.rb
+++ b/railties/lib/dispatcher.rb
@@ -49,9 +49,7 @@ class Dispatcher
     private
       def reset_application
         Dependencies.clear
-        ActiveRecord::Base.remove_subclasses
-        ActiveRecord::Observer.remove_subclasses
-        ActionController::Base.remove_subclasses
+        Dependencies.remove_subclasses_for(ActiveRecord::Base, ActiveRecord::Observer, ActionController::Base)
       end
     
       def controller_path(controller_name, module_name = nil)