diff --git a/lib/Jobs/MigrateGroups.php b/lib/Jobs/MigrateGroups.php
index 1ce9b9250..caaa31095 100644
--- a/lib/Jobs/MigrateGroups.php
+++ b/lib/Jobs/MigrateGroups.php
@@ -111,7 +111,7 @@ protected function migrateGroup(string $gid): bool {
 			$qb = $this->dbc->getQueryBuilder();
 			$affected = $qb->delete('groups')
 				->where($qb->expr()->eq('gid', $qb->createNamedParameter($gid)))
-				->execute();
+				->executeStatement();
 			if ($affected === 0) {
 				throw new \RuntimeException('Could not delete group from local backend');
 			}
@@ -141,14 +141,9 @@ protected function getGroupsToMigrate(array $samlGroups, array $pool): array {
 			if ($group === null) {
 				return false;
 			}
-			$reflected = new \ReflectionClass($group);
-			$backendsProperty = $reflected->getProperty('backends');
-			$backendsProperty->setAccessible(true);
-			$backends = $backendsProperty->getValue($group);
-			foreach ($backends as $backend) {
-				if ($backend instanceof Database) {
-					return true;
-				}
+			$backendNames = $group->getBackendNames();
+			if (in_array('Database', $backendNames, true)) {
+				return true;
 			}
 			return false;
 		});