diff --git a/src/backuptask.js b/src/backuptask.js
index def532164..081ffe93c 100644
--- a/src/backuptask.js
+++ b/src/backuptask.js
@@ -159,7 +159,7 @@ async function runBackupUpload(uploadConfig, progressCallback) {
         result = progress.result;
     }
 
-    const [error] = await safe(shell.promises.sudo(`backup-${remotePath}`, [ BACKUP_UPLOAD_CMD, remotePath, backupConfig.format, dataLayout.toString() ], { env: envCopy, preserveEnv: true, ipc: true, onMessage }));
+    const [error] = await safe(shell.promises.sudo(`backup-${remotePath}`, [ BACKUP_UPLOAD_CMD, remotePath, backupConfig.format, dataLayout.toString() ], { env: envCopy, preserveEnv: true, ipc: true, onMessage, outputHasTimestamps: true }));
     if (error && (error.code === null /* signal */ || (error.code !== 0 && error.code !== 50))) { // backuptask crashed
         throw new BoxError(BoxError.INTERNAL_ERROR, 'Backuptask crashed');
     } else if (error && error.code === 50) { // exited with error
diff --git a/src/shell.js b/src/shell.js
index c05a1b5d8..82a5c9b12 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -98,6 +98,8 @@ function sudo(tag, args, options, callback) {
 
     callback = once(callback); // exit may or may not be called after an 'error'
 
+    const logFunc = options.outputHasTimestamps ? process.stdoud.write : debug;
+
     if (options.ipc) {
         sudoArgs.push('--close-from=4'); // keep the ipc open. requires closefrom_override in sudoers file
         options.stdio = ['pipe', 'pipe', 'pipe', 'ipc'];
@@ -111,11 +113,9 @@ function sudo(tag, args, options, callback) {
 
     cp.stdout.on('data', (data) => {
         if (options.captureStdout) stdoutResult += data.toString('utf8');
-        if (!options.quiet) process.stdout.write(data); // do not use debug to avoid double timestamps when calling backupupload.js
-    });
-    cp.stderr.on('data', (data) => {
-        process.stderr.write(data);  // do not use debug to avoid double timestamps when calling backupupload.js
+        if (!options.quiet) logFunc(data.toString('utf8'));
     });
+    cp.stderr.on('data', (data) => logFunc(data.toString('utf8')));
 
     cp.on('exit', function (code, signal) {
         if (code === 0) return callback(null, options.captureStdout ? stdoutResult : null);