Carrierwave cannot remove image

I'm using Carrierwave for uploading image now. All nice, except one, - when I add checkbox for removing uploaded image I get error: "Can't mass-assign protected attributes: remove_image". Form: ``` ... <%= f.check_box :remove_image %> <%= f.label :remove_image, "remove image" %> ... ``` Model: ``` class Manufacturer < ActiveRecord::Base attr_accessible :name, :alias, :short_description, :long_description, :image, :publish, :position, :meta_keywords, :meta_description, :meta_title mount_uploader :image, ManufacturerUploader validates_presence_of :name, :alias validates_uniqueness_of :name, :alias validates_format_of :alias, :with => /^[a-z\d\-]*$/, :message => "a-z, 0-9 \' - \' ONLY" default_scope order('position ASC') before_destroy :remember_image after_destroy :remove_img protected def remember_image @image_name = self[:image] end def remove_img File.delete("#{Rails.root}/public/images/manufacturer/#{@image_name}") File.delete("#{Rails.root}/public/images/manufacturer/thumb_#{@image_name}") end end ``` Uploader: ``` class ManufacturerUploader < CarrierWave::Uploader::Base include CarrierWave::MiniMagick include Sprockets::Helpers::RailsHelper include Sprockets::Helpers::IsolatedHelper storage :file before :store, :remember_cache_id after :store, :delete_tmp_dir def remember_cache_id(new_file) @cache_id_was = cache_id end def delete_tmp_dir(new_file) if @cache_id_was.present? && @cache_id_was =~ /\A[\d]{8}\-[\d]{4}\-[\d]+\-[\d]{4}\z/ FileUtils.rm_rf(File.join(root, cache_dir, @cache_id_was)) end end def store_dir "images/#{model.class.to_s.underscore}" end def default_url "" + [version_name, "default.jpg"].compact.join('_') end process :resize_to_fit => [300, 300] version :thumb do process :resize_to_fit => [150, 150] end def extension_white_list %w(jpg jpeg gif png) end def filename "#{secure_token(10)}.#{file.extension}" if original_filename.present? end protected def secure_token(length=16) var = :"@#{mounted_as}_secure_token" model.instance_variable_get(var) or model.instance_variable_set(var, SecureRandom.hex(length/2)) end end ``` I think Carrierwave must to leverage :remove_image, but don't do it. What's wrong in this code?