diff --git a/apps/dav/lib/Provisioning/Apple/AppleProvisioningPlugin.php b/apps/dav/lib/Provisioning/Apple/AppleProvisioningPlugin.php
index 838c1fbb781a8..54818a890f393 100644
--- a/apps/dav/lib/Provisioning/Apple/AppleProvisioningPlugin.php
+++ b/apps/dav/lib/Provisioning/Apple/AppleProvisioningPlugin.php
@@ -133,7 +133,7 @@ public function httpGet(RequestInterface $request, ResponseInterface $response):
 		$filename = $userId . '-' . AppleProvisioningNode::FILENAME;
 
 		$xmlSkeleton = $this->getTemplate();
-		$body = vsprintf($xmlSkeleton, array_map(function ($v) {
+		$body = vsprintf($xmlSkeleton, array_map(function (string $v) {
 			return \htmlspecialchars($v, ENT_XML1, 'UTF-8');
 		}, [
 			$description,