diff --git a/Controller/BackendController.php b/Controller/BackendController.php
index 8d32f0d..fb06586 100644
--- a/Controller/BackendController.php
+++ b/Controller/BackendController.php
@@ -31,7 +31,7 @@ use phpOMS\Views\View;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class BackendController extends Controller
+final class BackendController extends Controller
 {
 
     /**
diff --git a/Models/Supplier.php b/Models/Supplier.php
index 73e3605..51496cc 100644
--- a/Models/Supplier.php
+++ b/Models/Supplier.php
@@ -25,7 +25,7 @@ use Modules\Profile\Models\Profile;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class Supplier
+final class Supplier
 {
     private $id = 0;
 
diff --git a/Models/SupplierMapper.php b/Models/SupplierMapper.php
index 7d84dcb..ea339c4 100644
--- a/Models/SupplierMapper.php
+++ b/Models/SupplierMapper.php
@@ -24,7 +24,7 @@ use phpOMS\DataStorage\Database\Query\Builder;
 use phpOMS\DataStorage\Database\Query\Column;
 use phpOMS\DataStorage\Database\RelationType;
 
-class SupplierMapper extends DataMapperAbstract
+final class SupplierMapper extends DataMapperAbstract
 {
     /**
      * Columns.