diff --git a/apps/files_external/lib/Controller/UserStoragesController.php b/apps/files_external/lib/Controller/UserStoragesController.php
index a3d582e35007b..e1e37432f03b2 100644
--- a/apps/files_external/lib/Controller/UserStoragesController.php
+++ b/apps/files_external/lib/Controller/UserStoragesController.php
@@ -108,7 +108,7 @@ public function index() {
 	 *
 	 * {@inheritdoc}
 	 */
-	public function show($id, $testOnly = true) {
+	public function show(int $id, $testOnly = true) {
 		return parent::show($id, $testOnly);
 	}