diff --git a/modules/backend/classes/FormWidgetBase.php b/modules/backend/classes/FormWidgetBase.php
index 668e19676..7d5f64733 100644
--- a/modules/backend/classes/FormWidgetBase.php
+++ b/modules/backend/classes/FormWidgetBase.php
@@ -66,6 +66,7 @@ abstract class FormWidgetBase extends WidgetBase
     {
         $id = parent::getId($suffix);
         $id .= '-' . $this->columnName;
+        $id = rtrim(str_replace(['[', ']'], '-', $id), '-');
         return $id;
     }