In my controller, I've got error when create action and try create model [can't mass-assignment], but in my spec, my test of mass-assignment model its pass!?! My Model: class Customer < ActiveRecord::Base attr_accessible :doc, :doc_rg, :name, :birthday, :name_sec, :address, :state_id, :city_id, :district_id, :customer_pj, :is_customer, :segment_id, :activity_id, :person_type, :person_id belongs_to :person , :polymorphic => true, dependent: :destroy has_many :histories has_many :emails def self.search(search) if search conditions = [] conditions << ['name LIKE ?', "%#{search}%"] find(:all, :conditions => conditions) else find(:all) end end end I`ve tired set attr_accessible in controller too, in my randomized way. the Controller: class CustomersController < ApplicationController include ActiveModel::MassAssignmentSecurity attr_accessible :doc, :doc_rg, :name, :birthday, :name_sec, :address, :state_id, :city_id, :district_id, :customer_pj, :is_customer autocomplete :business_segment, :name, :full => true autocomplete :business_activity, :name, :full => true [...] end The test, my passed test describe "accessible attributes" do it "should allow access to basics fields" do expect do @customer.save end.should_not raise_error(ActiveModel::MassAssignmentSecurity::Error) end end The error: ActiveModel::MassAssignmentSecurity::Error in CustomersController#create Can't mass-assign protected attributes: doc, doc_rg, name_sec, address, state_id, city_id, district_id, customer_pj, is_customer https://github.com/megabga/crm 1.9.2p320 Rails 3.2 MacOS pg