diff --git a/inc/Ui/Admin.php b/inc/Ui/Admin.php
index b79ade03b0..e6b0649b1b 100644
--- a/inc/Ui/Admin.php
+++ b/inc/Ui/Admin.php
@@ -21,7 +21,7 @@ class Admin extends Ui {
      */
     public function show() {
         $this->menu = $this->getPluginList();
-        echo '<div class="UI-admin">';
+        echo '<div class="ui-admin">';
         echo p_locale_xhtml('admin');
         $this->showSecurityCheck();
         $this->showAdminMenu();
diff --git a/lib/tpl/dokuwiki/css/_admin.less b/lib/tpl/dokuwiki/css/_admin.less
index cf219215f6..2cf8e3798e 100644
--- a/lib/tpl/dokuwiki/css/_admin.less
+++ b/lib/tpl/dokuwiki/css/_admin.less
@@ -1,4 +1,4 @@
-.dokuwiki div.UI-admin {
+.dokuwiki div.ui-admin {
 
     /* main task grouped in two columns */
     ul.admin_tasks {