diff --git a/lib/Album/AlbumMapper.php b/lib/Album/AlbumMapper.php
index 575c4da0..815238b9 100644
--- a/lib/Album/AlbumMapper.php
+++ b/lib/Album/AlbumMapper.php
@@ -332,6 +332,40 @@ class AlbumMapper {
 		return array_values(array_filter($collaborators, fn ($c) => $c !== null));
 	}
 
+
+	/**
+	 * @param int $albumId
+	 * @param string $userId
+	 * @return bool
+	 */
+	public function isCollaborator(int $albumId, string $userId): bool {
+		$query = $this->connection->getQueryBuilder();
+		$query->select("collaborator_id", "collaborator_type")
+			->from("photos_albums_collabs")
+			->where($query->expr()->eq('album_id', $query->createNamedParameter($albumId, IQueryBuilder::PARAM_INT)));
+
+		$rows = $query->executeQuery()->fetchAll();
+
+		foreach ($rows as $row) {
+			switch ($row['collaborator_type']) {
+				case self::TYPE_USER:
+					if ($row['collaborator_id'] === $userId) {
+						return true;
+					}
+					break;
+				case self::TYPE_GROUP:
+					if ($this->groupManager->isInGroup($userId, $row['collaborator_id'])) {
+						return true;
+					}
+					break;
+				default:
+					break;
+			}
+		}
+
+		return false;
+	}
+
 	/**
 	 * @param int $albumId
 	 * @param array{'id': string, 'type': int} $collaborators
diff --git a/lib/Sabre/Album/SharedAlbumRoot.php b/lib/Sabre/Album/SharedAlbumRoot.php
index d5dc9909..a6f84510 100644
--- a/lib/Sabre/Album/SharedAlbumRoot.php
+++ b/lib/Sabre/Album/SharedAlbumRoot.php
@@ -25,7 +25,6 @@ namespace OCA\Photos\Sabre\Album;
 
 use Sabre\DAV\Exception\Forbidden;
 use Sabre\DAV\Exception\Conflict;
-use OCA\Photos\Album\AlbumMapper;
 
 class SharedAlbumRoot extends AlbumRoot {
 	/**
@@ -47,11 +46,7 @@ class SharedAlbumRoot extends AlbumRoot {
 			throw new Conflict("File $sourceId is already in the folder");
 		}
 
-		$collaboratorIds = array_map(
-			fn ($collaborator) => $collaborator['type'].':'.$collaborator['id'],
-			$this->albumMapper->getCollaborators($this->album->getAlbum()->getId()),
-		);
-		if (!in_array(AlbumMapper::TYPE_USER.':'.$this->userId, $collaboratorIds)) {
+		if (!$this->albumMapper->isCollaborator($this->album->getAlbum()->getId(), $this->userId)) {
 			return false;
 		}