diff --git a/lib/ckeditor.rb b/lib/ckeditor.rb
index 98025d8d4..cd8eacbf6 100644
--- a/lib/ckeditor.rb
+++ b/lib/ckeditor.rb
@@ -36,8 +36,6 @@ module Backend
 
   DEFAULT_AUTHORIZE = -> {}
 
-  AUTHORIZATION_ADAPTERS = {}
-
   DEFAULT_CURRENT_USER = lambda do
     request.env['warden'].try(:user) || respond_to?(:current_user) && current_user
   end
@@ -127,11 +125,11 @@ def self.setup
   end
 
   def self.root_path
-    @root_path ||= Pathname.new(File.dirname(File.expand_path('../', __FILE__)))
+    @root_path ||= Pathname.new(File.dirname(File.expand_path(__dir__)))
   end
 
   def self.base_path
-    @base_path ||= (asset_path || File.join([Rails.application.config.assets.prefix, '/ckeditor/']))
+    @base_path ||= asset_path || File.join([Rails.application.config.assets.prefix, '/ckeditor/'])
   end
 
   # All css and js files from ckeditor folder
@@ -163,13 +161,12 @@ def self.picture_model(&block)
     if block_given?
       self.picture_model = block
     else
-      @@picture_model_class ||= begin
-        if @@picture_model.respond_to? :call
-          @@picture_model.call
-        else
-          @@picture_model || Ckeditor::Picture
-        end
-      end
+      @@picture_model_class ||= if @@picture_model.respond_to? :call
+                                  @@picture_model.call
+                                else
+                                  @@picture_model || Ckeditor::Picture
+                                end
+
     end
   end
 
@@ -186,13 +183,12 @@ def self.attachment_file_model(&block)
     if block_given?
       self.attachment_file_model = block
     else
-      @@attachment_file_model_class ||= begin
-        if @@attachment_file_model.respond_to? :call
-          @@attachment_file_model.call
-        else
-          @@attachment_file_model || Ckeditor::AttachmentFile
-        end
-      end
+      @@attachment_file_model_class ||= if @@attachment_file_model.respond_to? :call
+                                          @@attachment_file_model.call
+                                        else
+                                          @@attachment_file_model || Ckeditor::AttachmentFile
+                                        end
+
     end
   end
 
@@ -230,7 +226,7 @@ def self.authorize_with(*args, &block)
 
     if extension
       @authorize = lambda do
-        @authorization_adapter = Ckeditor::AUTHORIZATION_ADAPTERS[extension].new(*([self] + args).compact)
+        @authorization_adapter = Ckeditor.authorization_adapters[extension].new(*([self] + args).compact)
       end
     elsif block_given?
       @authorize = block
@@ -260,6 +256,10 @@ def self.assets_pipeline_enabled?
     @@assets_pipeline_enabled = Utils.assets_pipeline_enabled? if @@assets_pipeline_enabled.nil?
     @@assets_pipeline_enabled
   end
+
+  def self.authorization_adapters
+    @authorization_adapters ||= {}
+  end
 end
 
 require 'ckeditor/rails'
diff --git a/lib/ckeditor/hooks/action_policy.rb b/lib/ckeditor/hooks/action_policy.rb
index 23af57709..154d8c3b2 100644
--- a/lib/ckeditor/hooks/action_policy.rb
+++ b/lib/ckeditor/hooks/action_policy.rb
@@ -38,4 +38,4 @@ def authorized?(action, model_object = nil)
   end
 end
 
-Ckeditor::AUTHORIZATION_ADAPTERS[:action_policy] = Ckeditor::Hooks::ActionPolicyAuthorization
+Ckeditor.authorization_adapters[:action_policy] = Ckeditor::Hooks::ActionPolicyAuthorization
diff --git a/lib/ckeditor/hooks/cancan.rb b/lib/ckeditor/hooks/cancan.rb
index 7a96571d5..3337774eb 100644
--- a/lib/ckeditor/hooks/cancan.rb
+++ b/lib/ckeditor/hooks/cancan.rb
@@ -46,5 +46,5 @@ def current_ability
   end
 end
 
-Ckeditor::AUTHORIZATION_ADAPTERS[:cancan] = Ckeditor::Hooks::CanCanAuthorization
-Ckeditor::AUTHORIZATION_ADAPTERS[:cancancan] = Ckeditor::Hooks::CanCanAuthorization
+Ckeditor.authorization_adapters[:cancan] = Ckeditor::Hooks::CanCanAuthorization
+Ckeditor.authorization_adapters[:cancancan] = Ckeditor::Hooks::CanCanAuthorization
diff --git a/lib/ckeditor/hooks/pundit.rb b/lib/ckeditor/hooks/pundit.rb
index f1cfb4cc9..0bdb7cbce 100644
--- a/lib/ckeditor/hooks/pundit.rb
+++ b/lib/ckeditor/hooks/pundit.rb
@@ -43,4 +43,4 @@ def current_user_for_pundit
   end
 end
 
-Ckeditor::AUTHORIZATION_ADAPTERS[:pundit] = Ckeditor::Hooks::PunditAuthorization
+Ckeditor.authorization_adapters[:pundit] = Ckeditor::Hooks::PunditAuthorization
diff --git a/lib/generators/ckeditor/install_generator.rb b/lib/generators/ckeditor/install_generator.rb
index e56ac9e22..623d826e3 100644
--- a/lib/generators/ckeditor/install_generator.rb
+++ b/lib/generators/ckeditor/install_generator.rb
@@ -14,8 +14,8 @@ class InstallGenerator < Rails::Generators::Base
       class_option :orm, type: :string, default: 'active_record',
                          desc: 'Backend processor for upload support'
 
-      class_option :backend, type: :string, default: 'paperclip',
-                             desc: 'paperclip (default), active_storage, carrierwave or dragonfly'
+      class_option :backend, type: :string, default: 'active_storage',
+                             desc: 'active_storage (default), paperclip, carrierwave or dragonfly'
 
       def self.source_root
         @source_root ||= File.expand_path(File.join(File.dirname(__FILE__), 'templates'))
@@ -43,7 +43,7 @@ def mount_engine
       end
 
       def create_models
-        [:asset, :picture, :attachment_file].each do |filename|
+        %w[asset picture attachment_file].each do |filename|
           template "#{generator_dir}/ckeditor/#{filename}.rb",
                    File.join('app/models', ckeditor_dir, "#{filename}.rb")
         end
@@ -67,7 +67,7 @@ def create_uploaders
       def create_ckeditor_migration
         return unless ['active_record'].include?(orm)
 
-        migration_template "#{generator_dir}/migration.rb",
+        migration_template "#{generator_dir}/create_ckeditor_assets.rb",
                            File.join('db/migrate', 'create_ckeditor_assets.rb')
       end
 
@@ -102,7 +102,7 @@ def orm
       end
 
       def backend
-        (options[:backend] || 'paperclip').to_s
+        (options[:backend] || 'active_storage').to_s
       end
     end
   end