diff --git a/src/script.php b/src/script.php
index dcbfa07..e73bab4 100644
--- a/src/script.php
+++ b/src/script.php
@@ -93,6 +93,7 @@ class Tpl_MokoonyxInstallerScript implements InstallerScriptInterface
             $this->migrateFromCassiopeia();
             $this->replaceCassiopeiaReferences();
             $this->clearFaviconStamp();
+            $this->lockExtension();
         }
 
         return true;
@@ -378,6 +379,29 @@ class Tpl_MokoonyxInstallerScript implements InstallerScriptInterface
         }
     }
 
+    /**
+     * Lock the extension to prevent uninstallation via Extension Manager.
+     */
+    private function lockExtension(): void
+    {
+        $db = Factory::getDbo();
+
+        try {
+            $query = $db->getQuery(true)
+                ->update('#__extensions')
+                ->set($db->quoteName('locked') . ' = 1')
+                ->where($db->quoteName('element') . ' = ' . $db->quote(self::NEW_NAME))
+                ->where($db->quoteName('type') . ' = ' . $db->quote('template'));
+            $db->setQuery($query)->execute();
+
+            if ($db->getAffectedRows() > 0) {
+                $this->logMessage('MokoOnyx extension locked.');
+            }
+        } catch (\Throwable $e) {
+            $this->logMessage('Failed to lock extension: ' . $e->getMessage(), 'warning');
+        }
+    }
+
     private function logMessage(string $message, string $priority = 'info'): void
     {
         $priorities = [