diff --git a/promotions/lib/controllers/backend/solidus_promotions/admin/promotion_codes_controller.rb b/promotions/lib/controllers/backend/solidus_promotions/admin/promotion_codes_controller.rb
index ee23a457469..0310fc54ceb 100644
--- a/promotions/lib/controllers/backend/solidus_promotions/admin/promotion_codes_controller.rb
+++ b/promotions/lib/controllers/backend/solidus_promotions/admin/promotion_codes_controller.rb
@@ -48,6 +48,10 @@ def create
 
       private
 
+      def model_class
+        SolidusPromotions::PromotionCode
+      end
+
       def load_promotion
         @promotion = SolidusPromotions::Promotion
           .accessible_by(current_ability, :show)