diff --git a/core/profiles/demo_umami/themes/umami/umami.theme b/core/profiles/demo_umami/themes/umami/umami.theme
index 1181242b7cd37a33d4f3423568fc60c7daa9c0cc..ac2bedd9406e7593fa82dd2836f79e8b0d60c219 100644
--- a/core/profiles/demo_umami/themes/umami/umami.theme
+++ b/core/profiles/demo_umami/themes/umami/umami.theme
@@ -39,10 +39,10 @@ function umami_preprocess_field(&$variables, $hook) {
       $element['#field_name'] == 'field_recipe_category' ||
       $element['#field_name'] == 'field_tags' ||
       $element['#field_name'] == 'field_difficulty') {
-      $variables['attributes']['class'] = 'label-items';
+      $variables['attributes']['class'][] = 'label-items';
 
       if ($element['#view_mode'] == 'card' && $element['#field_name'] == 'field_difficulty') {
-        $variables['attributes']['class'] = 'umami-card__label-items';
+        $variables['attributes']['class'][] = 'umami-card__label-items';
       }
     }
   }