diff --git a/apps/files_external/service/dbconfigservice.php b/apps/files_external/service/dbconfigservice.php
index 9f7061eb938d..802742b829ea 100644
--- a/apps/files_external/service/dbconfigservice.php
+++ b/apps/files_external/service/dbconfigservice.php
@@ -195,7 +195,7 @@ public function addMount($mountPoint, $storageBackend, $authBackend, $priority,
 				'type' => $builder->createNamedParameter($type, IQueryBuilder::PARAM_INT)
 			]);
 		$query->execute();
-		return (int)$this->connection->lastInsertId('external_mounts');
+		return (int)$this->connection->lastInsertId('*PREFIX*external_mounts');
 	}
 
 	/**