diff --git a/Controller/ApiController.php b/Controller/ApiController.php
index 0bbfb1b..87c2b4d 100644
--- a/Controller/ApiController.php
+++ b/Controller/ApiController.php
@@ -38,7 +38,7 @@ use Modules\Exchange\Models\PermissionState;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class ApiController extends Controller
+final class ApiController extends Controller
 {
 
     /**
diff --git a/Controller/BackendController.php b/Controller/BackendController.php
index cb15d22..097b741 100644
--- a/Controller/BackendController.php
+++ b/Controller/BackendController.php
@@ -38,7 +38,7 @@ use Modules\Exchange\Models\PermissionState;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class BackendController extends Controller
+final class BackendController extends Controller
 {
 
     public function viewExchangeDashboard(RequestAbstract $request, ResponseAbstract $response, $data = null) : \Serializable
diff --git a/Models/InterfaceManagerMapper.php b/Models/InterfaceManagerMapper.php
index c443511..5bf66ec 100644
--- a/Models/InterfaceManagerMapper.php
+++ b/Models/InterfaceManagerMapper.php
@@ -27,7 +27,7 @@ use phpOMS\DataStorage\Database\RelationType;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class InterfaceManagerMapper extends DataMapperAbstract
+final class InterfaceManagerMapper extends DataMapperAbstract
 {
 
     /**