diff --git a/apps/user_ldap/tests/AccessTest.php b/apps/user_ldap/tests/AccessTest.php
index 16feadf81496e..2a0788da0a422 100644
--- a/apps/user_ldap/tests/AccessTest.php
+++ b/apps/user_ldap/tests/AccessTest.php
@@ -713,7 +713,7 @@ public function testUserStateUpdate(): void {
 			->method('__get')
 			->willReturnMap([
 				[ 'ldapUserDisplayName', 'displayName' ],
-				[ 'ldapUserDisplayName2', null],
+				[ 'ldapUserDisplayName2', ''],
 			]);
 
 		$offlineUserMock = $this->createMock(OfflineUser::class);