diff --git a/apps/user_ldap/lib/Access.php b/apps/user_ldap/lib/Access.php
index aba397f4f09ee..1bea2593eb9a4 100644
--- a/apps/user_ldap/lib/Access.php
+++ b/apps/user_ldap/lib/Access.php
@@ -397,6 +397,7 @@ public function getDomainDNFromDN($dn) {
 		$domainParts = [];
 		$dcFound = false;
 		foreach ($allParts as $part) {
+			if (!is_string($part)) continue;
 			if (!$dcFound && str_starts_with($part, 'dc=')) {
 				$dcFound = true;
 			}