diff --git a/Models/NullWikiCategory.php b/Models/NullWikiCategory.php
index 8783829..74fcb4e 100644
--- a/Models/NullWikiCategory.php
+++ b/Models/NullWikiCategory.php
@@ -22,6 +22,6 @@ namespace Modules\Knowledgebase\Models;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-class NullWikiCategory extends WikiCategory
+final class NullWikiCategory extends WikiCategory
 {
 }
diff --git a/Models/NullWikiDoc.php b/Models/NullWikiDoc.php
index f12272f..22aeb54 100644
--- a/Models/NullWikiDoc.php
+++ b/Models/NullWikiDoc.php
@@ -22,6 +22,6 @@ namespace Modules\Knowledgebase\Models;
  * @link    https://orange-management.org
  * @since   1.0.0
  */
-class NullWikiDoc extends WikiDoc
+final class NullWikiDoc extends WikiDoc
 {
 }