diff --git a/services/filestore/app/js/GcsPersistor.js b/services/filestore/app/js/GcsPersistor.js
index 5a44132882..799ee65905 100644
--- a/services/filestore/app/js/GcsPersistor.js
+++ b/services/filestore/app/js/GcsPersistor.js
@@ -184,7 +184,7 @@ async function deleteFile(bucketName, key) {
       await file.copy(
         storage
           .bucket(`${bucketName}${settings.filestore.gcs.deletedBucketSuffix}`)
-          .file(`${key}-${new Date()}`)
+          .file(`${key}-${new Date().toISOString()}`)
       )
     }
     if (settings.filestore.gcs.unlockBeforeDelete) {
diff --git a/services/filestore/test/acceptance/js/FilestoreTests.js b/services/filestore/test/acceptance/js/FilestoreTests.js
index dc31d1a83c..272ffb52bd 100644
--- a/services/filestore/test/acceptance/js/FilestoreTests.js
+++ b/services/filestore/test/acceptance/js/FilestoreTests.js
@@ -453,7 +453,7 @@ describe('Filestore', function() {
             await TestHelper.expectPersistorToHaveFile(
               app.persistor,
               `${Settings.filestore.stores.user_files}-deleted`,
-              `${projectId}/${fileId}-${date}`,
+              `${projectId}/${fileId}-${date.toISOString()}`,
               content
             )
           })