diff --git a/src/bundle/Resources/views/themes/admin/ui/form_fields.html.twig b/src/bundle/Resources/views/themes/admin/ui/form_fields.html.twig
index 32d5e1470a..13fda1ba69 100644
--- a/src/bundle/Resources/views/themes/admin/ui/form_fields.html.twig
+++ b/src/bundle/Resources/views/themes/admin/ui/form_fields.html.twig
@@ -233,7 +233,7 @@
 {%- block richtext_widget -%}
     {% set attr = attr|merge({ 'hidden': true }) %}
 
-    <div class="ibexa-data-source">
+    <div class="ibexa-data-source ibexa-data-source--richtext">
         <textarea {{ block('widget_attributes') }}>{{ value }}</textarea>
         <div class="hidden" data-udw-config-name="richtext_embed" data-udw-config="{{ ibexa_udw_config('richtext_embed', udw_context) }}"></div>
         <div class="hidden" data-udw-config-name="richtext_embed_image" data-udw-config="{{ ibexa_udw_config('richtext_embed_image', udw_context) }}"></div>