diff --git a/src/backupformat/rsync.js b/src/backupformat/rsync.js
index fc47157e3..6c7156f9b 100644
--- a/src/backupformat/rsync.js
+++ b/src/backupformat/rsync.js
@@ -284,7 +284,7 @@ async function upload(backupTarget, remotePath, dataLayout, progressCallback) {
 
     await saveFsMetadata(dataLayout, `${dataLayout.localRoot()}/fsmetadata.json`);
     const { stats, integrity } = await sync(backupTarget, remotePath, dataLayout, progressCallback);
-    const integrityDataJsonString = JSON.stringify(integrity, null, 2);
+    const integrityDataJsonString = JSON.stringify(Object.fromEntries(integrity), null, 2);
     const integrityDataStream = Readable.from(integrityDataJsonString);
     const integrityUploader = await backupTargets.storageApi(backupTarget).upload(backupTarget.config, `${remotePath}.checksum`);
     await stream.pipeline(integrityDataStream, integrityUploader.stream);
diff --git a/src/backupformat/tgz.js b/src/backupformat/tgz.js
index 860bfac89..6874e501e 100644
--- a/src/backupformat/tgz.js
+++ b/src/backupformat/tgz.js
@@ -258,7 +258,7 @@ async function upload(backupTarget, remotePath, dataLayout, progressCallback) {
 
         const integrityMap = new Map();
         integrityMap.set(path.basename(remotePath), integrity);
-        const integrityDataJsonString = JSON.stringify([...integrityMap], null, 2);
+        const integrityDataJsonString = JSON.stringify(Object.fromEntries(integrityMap), null, 2);
         const integrityDataStream = Readable.from(integrityDataJsonString);
         const integrityUploader = await backupTargets.storageApi(backupTarget).upload(backupTarget.config, `${remotePath}.checksum`);
         await stream.pipeline(integrityDataStream, integrityUploader.stream);