diff --git a/ext_localconf.php b/ext_localconf.php
new file mode 100644
index 0000000..1311df1
--- /dev/null
+++ b/ext_localconf.php
@@ -0,0 +1,10 @@
+<?php
+defined('TYPO3') || die('Access denied.');
+
+call_user_func(
+    function ($extKey) {
+        // @todo TYPO3v11 removal: remove toolbar items registration via ext_localconf.php
+        $GLOBALS['TYPO3_CONF_VARS']['BE']['toolbarItems'][1502345259] = \JosefGlatz\BeuserFastswitch\Hooks\Backend\Toolbar\BackendUserPreviewToolbarItem::class;
+    },
+    'beuser_fastswitch'
+);