diff --git a/Controller.php b/Controller.php
index 298a281..fd4db94 100644
--- a/Controller.php
+++ b/Controller.php
@@ -41,7 +41,7 @@ use Modules\Organization\Models\PermissionState;
  * @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/NullDepartment.php b/Models/NullDepartment.php
index b52a458..8dcb6ef 100644
--- a/Models/NullDepartment.php
+++ b/Models/NullDepartment.php
@@ -22,6 +22,6 @@ namespace Modules\Organization\Models;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class NullDepartment extends Department
+final class NullDepartment extends Department
 {
 }
diff --git a/Models/NullPosition.php b/Models/NullPosition.php
index bd59973..a67b275 100644
--- a/Models/NullPosition.php
+++ b/Models/NullPosition.php
@@ -22,6 +22,6 @@ namespace Modules\Organization\Models;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class NullPosition extends Position
+final class NullPosition extends Position
 {
 }
diff --git a/Models/NullUnit.php b/Models/NullUnit.php
index 725b889..d7afb47 100644
--- a/Models/NullUnit.php
+++ b/Models/NullUnit.php
@@ -22,6 +22,6 @@ namespace Modules\Organization\Models;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class NullUnit extends Unit
+final class NullUnit extends Unit
 {
 }