diff --git a/app/models/product_categories_block.rb b/app/models/product_categories_block.rb
index c67a499..c361c07 100644
--- a/app/models/product_categories_block.rb
+++ b/app/models/product_categories_block.rb
@@ -33,7 +33,7 @@ class ProductCategoriesBlock < Block
     end
   end
 
-  DISPLAY_OPTIONS['catalog_only'] = __('Only on the catalog')
+  DISPLAY_OPTIONS = DISPLAY_OPTIONS.merge('catalog_only' => _('Only on the catalog'))
 
   def display
     settings[:display].nil? ? 'catalog_only' : super
--
libgit2 0.21.2