diff --git a/forms/gridfield/GridFieldDetailForm.php b/forms/gridfield/GridFieldDetailForm.php
index 123bdd87c..31fe37c88 100644
--- a/forms/gridfield/GridFieldDetailForm.php
+++ b/forms/gridfield/GridFieldDetailForm.php
@@ -332,8 +332,8 @@ class GridFieldDetailForm_ItemRequest extends RequestHandler {
 			$form->setAttribute('data-pjax-fragment', 'CurrentForm Content');
 			if($form->Fields()->hasTabset()) {
 				$form->Fields()->findOrMakeTab('Root')->setTemplate('CMSTabSet');
-				$form->addExtraClass('ss-tabset');
-			}
+				$form->addExtraClass('ss-tabset cms-tabset');
+		 	}
 
 			if($toplevelController->hasMethod('Backlink')) {
 				$form->Backlink = $toplevelController->Backlink();