diff --git a/addons/website_mass_mailing/views/website_mass_mailing.xml b/addons/website_mass_mailing/views/website_mass_mailing.xml
index ad5d201343a..449c1773b6d 100644
--- a/addons/website_mass_mailing/views/website_mass_mailing.xml
+++ b/addons/website_mass_mailing/views/website_mass_mailing.xml
@@ -5,6 +5,7 @@
 <template id="assets_frontend" inherit_id="website.assets_frontend" name="Mail Frontend Assets">
     <xpath expr="." position="inside">
         <script type="text/javascript" src="/website_mass_mailing/static/src/js/website_mass_mailing.js"></script>
+        <link rel="stylesheet" href="/mass_mailing/static/src/css/mass_mailing_popup.css" type="text/css"/>
     </xpath>
 </template>