diff --git a/Models/NullSession.php b/Models/NullSession.php
index 03bd713..74709aa 100644
--- a/Models/NullSession.php
+++ b/Models/NullSession.php
@@ -22,6 +22,6 @@ namespace Modules\HumanResourceTimeRecording\Models;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-class NullSession extends Session
+final class NullSession extends Session
 {
 }
diff --git a/Models/NullSessionElement.php b/Models/NullSessionElement.php
index 65bf830..5dc823e 100644
--- a/Models/NullSessionElement.php
+++ b/Models/NullSessionElement.php
@@ -22,6 +22,6 @@ namespace Modules\HumanResourceTimeRecording\Models;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-class NullSessionElement extends SessionElement
+final class NullSessionElement extends SessionElement
 {
 }