diff --git a/src/backupformat/tgz.js b/src/backupformat/tgz.js
index 7f91afd74..f7301ceb7 100644
--- a/src/backupformat/tgz.js
+++ b/src/backupformat/tgz.js
@@ -256,14 +256,15 @@ async function upload(backupTarget, remotePath, dataLayout, progressCallback) {
         const uploader = await backupTargets.storageApi(backupTarget).upload(backupTarget.config, remotePath);
         const { stats, integrity } = await tarPack(dataLayout, backupTarget.encryption, uploader, progressCallback);
 
-        const checksumData = [{ filename: path.basename(remotePath), ...integrity }];
-        const checksumDataJsonString = JSON.stringify(checksumData, null, 4);
-        const checksumDataStream = Readable.from(checksumDataJsonString);
-        const checksumUploader = await backupTargets.storageApi(backupTarget).upload(backupTarget.config, `${remotePath}.checksum`);
-        await stream.pipeline(checksumDataStream, checksumUploader.stream);
-        await checksumUploader.finish();
+        const integrityMap = new Map();
+        integrityMap.set(path.basename(remotePath), ...integrity);
+        const integrityDataJsonString = JSON.stringify([...integrityMap], null, 4);
+        const integrityDataStream = Readable.from(integrityDataJsonString);
+        const integrityUploader = await backupTargets.storageApi(backupTarget).upload(backupTarget.config, `${remotePath}.checksum`);
+        await stream.pipeline(integrityDataStream, integrityUploader.stream);
+        await integrityUploader.finish();
 
-        integrity.signature = await crypto.sign(null /* algorithm */, checksumDataJsonString, backupTarget.integrityKeyPair.privateKey);
+        integrity.signature = await crypto.sign(null /* algorithm */, integrityDataJsonString, backupTarget.integrityKeyPair.privateKey);
         return { stats, integrity };
     });
 }