diff --git a/core/admin/mailu/ui/templates/sidebar.html b/core/admin/mailu/ui/templates/sidebar.html
index a8c057f5..0fdae9db 100644
--- a/core/admin/mailu/ui/templates/sidebar.html
+++ b/core/admin/mailu/ui/templates/sidebar.html
@@ -126,7 +126,7 @@
       {% else %}
       <li class="nav-item">
         <a href="{{ url_for('.login') }}" class="nav-link">
-          <i class="nav-icon fa fa-sign-in"></i>
+          <i class="nav-icon fas fa-sign-in-alt"></i>
           <p class="text">{% trans %}Sign in{% endtrans %}</p>
         </a>
       </li>