diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 7e9220e..399b368 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -3,7 +3,7 @@ class ApplicationController < ActionController::Base
   before_action :authenticate_user!
   before_action :set_locale
   layout :layout_by_resource
-  after_filter :set_headers
+  after_action :set_headers
 
   def set_locale
     I18n.locale = params[:lang] || I18n.default_locale
diff --git a/config/application.rb b/config/application.rb
index 582e934..7622a71 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -13,6 +13,7 @@ module InvoiceKeeper
     # -- all .rb files in that directory are automatically loaded.
     config.i18n.load_path += Dir[Rails.root.join('config', 'locales', '**', '*.{rb,yml}').to_s]
     config.i18n.default_locale = :pl
+    config.action_dispatch.default_headers.merge!({'X-Frame-Options' => 'ALLOWALL'})
     config.middleware.insert_before 0, Rack::Cors do
       allow do
         origins '*'