diff --git a/classes/table/participants.php b/classes/table/participants.php
index e41ca55..f1e6276 100644
--- a/classes/table/participants.php
+++ b/classes/table/participants.php
@@ -43,6 +43,12 @@
  */
 class participants extends \core_user\table\participants {
 
+    /**
+     * A list of roles that current user can view in a context.
+     * @var array
+     */
+    protected $viewableroles;
+
     /**
      * @var bool|mixed Is recompletion enabled in this course.
      */