diff --git a/Models/NullCalendar.php b/Models/NullCalendar.php
index 566b58b..77ba83a 100644
--- a/Models/NullCalendar.php
+++ b/Models/NullCalendar.php
@@ -22,7 +22,7 @@ namespace Modules\Calendar\Models;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-class NullCalendar extends Calendar
+final class NullCalendar extends Calendar
 {
 
 }
diff --git a/Models/NullEvent.php b/Models/NullEvent.php
index fc4c473..aa3e1cc 100644
--- a/Models/NullEvent.php
+++ b/Models/NullEvent.php
@@ -22,7 +22,7 @@ namespace Modules\Calendar\Models;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-class NullEvent extends Event
+final class NullEvent extends Event
 {
 
 }
diff --git a/Models/NullSchedule.php b/Models/NullSchedule.php
index 5ad3a7c..d8542f4 100644
--- a/Models/NullSchedule.php
+++ b/Models/NullSchedule.php
@@ -22,6 +22,6 @@ namespace Modules\Calendar\Models;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-class NullSchedule extends Schedule
+final class NullSchedule extends Schedule
 {
 }