diff --git a/lib/Db/FaceDetectionMapper.php b/lib/Db/FaceDetectionMapper.php
index 2f7ff83f..3a8da900 100644
--- a/lib/Db/FaceDetectionMapper.php
+++ b/lib/Db/FaceDetectionMapper.php
@@ -275,6 +275,7 @@ public function findDetectionForPreviewImageByClusterId(int $clusterId) : FaceDe
 		try {
 			return $this->findEntity($qb);
 		} catch (DoesNotExistException $e) {
+			$qb = $this->db->getQueryBuilder();
 			$qb->select(array_map(fn ($col) => 'd.'.$col, FaceDetection::$columns))
 				->from('recognize_face_detections', 'd')
 				->where($qb->expr()->eq('d.cluster_id', $qb->createPositionalParameter($clusterId)))