diff --git a/Controller/BackendController.php b/Controller/BackendController.php
index 94e49b0..36d3df1 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/Answer.php b/Models/Answer.php
index 1b04645..79e4b78 100644
--- a/Models/Answer.php
+++ b/Models/Answer.php
@@ -22,7 +22,7 @@ namespace Modules\Surveys;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class Answer
+final class Answer
 {
 
     /**
diff --git a/Models/Question.php b/Models/Question.php
index 762d99b..2a7b4fc 100644
--- a/Models/Question.php
+++ b/Models/Question.php
@@ -22,7 +22,7 @@ namespace Modules\Surveys;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class Question
+final class Question
 {
 
     /**
diff --git a/Models/Section.php b/Models/Section.php
index 0a41b06..f1d47c4 100644
--- a/Models/Section.php
+++ b/Models/Section.php
@@ -22,7 +22,7 @@ namespace Modules\Surveys;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class Section
+final class Section
 {
 
     /**
diff --git a/Models/Survey.php b/Models/Survey.php
index 0691a9a..e10c4d0 100644
--- a/Models/Survey.php
+++ b/Models/Survey.php
@@ -22,7 +22,7 @@ namespace Modules\Surveys;
  * @link       http://website.orange-management.de
  * @since      1.0.0
  */
-class Survey
+final class Survey
 {
 
     /**