diff --git a/services/history-v1/storage/lib/scan.js b/services/history-v1/storage/lib/scan.js
index 1f2a335254..d55f5362c1 100644
--- a/services/history-v1/storage/lib/scan.js
+++ b/services/history-v1/storage/lib/scan.js
@@ -1,3 +1,7 @@
+// @ts-check
+
+'use strict'
+
 const logger = require('@overleaf/logger')
 const { JobNotFoundError, JobNotReadyError } = require('./chunk_store/errors')
 const BATCH_SIZE = 1000 // Default batch size for SCAN