diff --git a/core/admin/mailu/sso/templates/form_sso.html b/core/admin/mailu/sso/templates/form_sso.html
index d2451597..d713251e 100644
--- a/core/admin/mailu/sso/templates/form_sso.html
+++ b/core/admin/mailu/sso/templates/form_sso.html
@@ -3,6 +3,7 @@
 {%- block content %}
 {%- call macros.card() %}
 <form class="form" method="post" role="form">
+  {{ form.hidden_tag() }}
   {{ macros.form_field(form.email) }}
   {{ macros.form_field(form.pw) }}
   {{ macros.form_fields(fields, label=False, class="btn btn-default") }}