diff --git a/lib/classes/plugininfo/calendartype.php b/lib/classes/plugininfo/calendartype.php
index 5e81a570c07..9e999c2db04 100644
--- a/lib/classes/plugininfo/calendartype.php
+++ b/lib/classes/plugininfo/calendartype.php
@@ -23,6 +23,8 @@
  */
 namespace core\plugininfo;
 
+use part_of_admin_tree, admin_settingpage;
+
 defined('MOODLE_INTERNAL') || die();
 
 /**