diff --git a/templates/bootstrap4/preview_iframe.tpl b/templates/bootstrap4/preview_iframe.tpl
index 870a6b1e..787a1b92 100644
--- a/templates/bootstrap4/preview_iframe.tpl
+++ b/templates/bootstrap4/preview_iframe.tpl
@@ -44,3 +44,4 @@
     <script src="{serendipity_getFile file="theme.js" frontend=true}"></script>
 </body>
 </html>
+{/if}