diff --git a/modules/backend/formwidgets/FieldSet.php b/modules/backend/formwidgets/FieldSet.php
index 9a7d46ca8..30da54b08 100644
--- a/modules/backend/formwidgets/FieldSet.php
+++ b/modules/backend/formwidgets/FieldSet.php
@@ -26,6 +26,11 @@ class FieldSet extends FormWidgetBase
      */
     public $form;
 
+    /**
+     * @var array Field configuration
+     */
+    public $fields;
+
     /**
      * @var bool Determines if this form field should display comments and labels.
      */