diff --git a/Controller.php b/Controller.php
index 5fdb1ea..492b17a 100644
--- a/Controller.php
+++ b/Controller.php
@@ -44,7 +44,7 @@ use phpOMS\DataStorage\Database\RelationType;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class Controller extends ModuleAbstract implements WebInterface
+final class Controller extends ModuleAbstract implements WebInterface
 {
 
     /**
diff --git a/Models/NullTask.php b/Models/NullTask.php
index 598f0fd..9c71b5f 100644
--- a/Models/NullTask.php
+++ b/Models/NullTask.php
@@ -22,7 +22,7 @@ namespace Modules\Tasks\Models;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class NullTask extends Task
+final class NullTask extends Task
 {
 
 }
diff --git a/Models/NullTaskElement.php b/Models/NullTaskElement.php
index 00ec484..fa87dfc 100644
--- a/Models/NullTaskElement.php
+++ b/Models/NullTaskElement.php
@@ -22,7 +22,7 @@ namespace Modules\Tasks\Models;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class NullTaskElement extends TaskElement
+final class NullTaskElement extends TaskElement
 {
 
 }