diff --git a/Modules/OrgUnit/classes/PathStorage/class.ilOrgUnitPathStorage.php b/Modules/OrgUnit/classes/PathStorage/class.ilOrgUnitPathStorage.php
index c6e3fa3a7053..f13c015391a9 100644
--- a/Modules/OrgUnit/classes/PathStorage/class.ilOrgUnitPathStorage.php
+++ b/Modules/OrgUnit/classes/PathStorage/class.ilOrgUnitPathStorage.php
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * This file is part of ILIAS, a powerful learning management system
  * published by ILIAS open source e-Learning e.V.
@@ -16,6 +17,8 @@
  ********************************************************************
  */
 
+declare(strict_types=1);
+
 /**
  * Class ilOrgUnitPathStorage
  * @author Fabian Schmid <fs@studer-raimann.ch>
@@ -150,7 +153,7 @@ public static function writePathByRefId(string $ref_id): void
             $last = array_pop($path);
             $middle = implode(self::GLUE_SIMPLE, $path);
             if (strlen($middle) > self::MAX_MIDDLE_PATH_LENGTH) {
-                $middle = substr($middle, 0, self::MAX_MIDDLE_PATH_LENGTH) . " ...";
+                $middle = mb_substr($middle, 0, self::MAX_MIDDLE_PATH_LENGTH) . " ...";
             }
             $expression = implode(self::GLUE_SIMPLE, [$first, $middle, $last]);
         } else {