diff --git a/templates/SilverStripe/CMS/Controllers/Includes/CMSMain_PreviewPanel.ss b/templates/SilverStripe/CMS/Controllers/Includes/CMSMain_PreviewPanel.ss
index 9500d96b..70dc2e00 100644
--- a/templates/SilverStripe/CMS/Controllers/Includes/CMSMain_PreviewPanel.ss
+++ b/templates/SilverStripe/CMS/Controllers/Includes/CMSMain_PreviewPanel.ss
@@ -1,9 +1,11 @@
 <div class="cms-preview fill-height flexbox-area-grow" data-layout-type="border">
-	<div class="panel panel--scrollable flexbox-area-grow">
+	<div class="panel panel--scrollable flexbox-area-grow fill-height">
 		<div class="preview-note"><span><!-- --></span><%t CMSPageHistoryController_versions_ss.PREVIEW 'Website preview' %></div>
-		<div class="preview-device-outer">
-			<div class="preview-device-inner">
-				<iframe src="about:blank" class="center" name="cms-preview-iframe"></iframe>
+		<div class="preview__device">
+			<div class="preview-device-outer">
+				<div class="preview-device-inner">
+					<iframe src="about:blank" class="center" name="cms-preview-iframe"></iframe>
+				</div>
 			</div>
 		</div>
 	</div>