Use set_view_path intead of view_path=

lib/generators/simple_controller/templates/controllers/controller.rb.tt

 class <%= controller_class_name %>Controller < SimpleController::BaseController
-  view_path = '<%= view_class_path %>'
+  set_view_path '<%= view_class_path %>'
   <% if auth.present? %>acts_as_auth_action :<%= auth.downcase %><% end %>
 
   private

lib/simple_controller/base_controller.rb

@@ -15,7 +15,7 @@ class SimpleController::BaseController < ::InheritedResources::Base
 
   protected
 
-  def self.view_path= path
+  def self.set_view_path path
     @view_path = path
   end