diff --git a/app/code/Magento/Backend/view/adminhtml/templates/widget/form/renderer/fieldset.phtml b/app/code/Magento/Backend/view/adminhtml/templates/widget/form/renderer/fieldset.phtml
index fedec572af962a86661de9308ea78095fff09b64..41f6bf34afc8a9184e5bab7dca4e516e0c2055c4 100644
--- a/app/code/Magento/Backend/view/adminhtml/templates/widget/form/renderer/fieldset.phtml
+++ b/app/code/Magento/Backend/view/adminhtml/templates/widget/form/renderer/fieldset.phtml
@@ -22,7 +22,7 @@ if (!isset($advancedLabel)) {
     $advancedLabel = __('Additional Settings');
 }
 
-$cssClass = ($isField) ? 'field ' . $element->getClass() : 'fieldset admin__fieldset' . $element->getClass();
+$cssClass = ($isField) ? 'field ' . $element->getClass() : 'fieldset admin__fieldset ' . $element->getClass();
 
 if ($isField) {
     $count = $element->getCountBasicChildren();