diff --git a/includes/Api/OrdersController.php b/includes/Api/OrdersController.php
index 52b2d81..3b770ca 100644
--- a/includes/Api/OrdersController.php
+++ b/includes/Api/OrdersController.php
@@ -1295,8 +1295,8 @@ class OrdersController {
                 $value = $term ? $term->name : $value;
               }
             } else {
-              // Custom attribute - WooCommerce stores as 'attribute_' + exact attribute name
-              $meta_key = 'attribute_' . $attr_name;
+              // Custom attribute - WooCommerce stores as 'attribute_' + lowercase sanitized name
+              $meta_key = 'attribute_' . sanitize_title( $attr_name );
               $value = get_post_meta( $variation_id, $meta_key, true );
               
               // Capitalize the attribute name for display