diff --git a/src/backuptask.js b/src/backuptask.js
index 91ed433cf..d1442c04c 100644
--- a/src/backuptask.js
+++ b/src/backuptask.js
@@ -164,7 +164,8 @@ async function runBackupUpload(uploadConfig, progressCallback) {
         result = progress.result;
     }
 
-    const [error] = await safe(shell.promises.sudo([ BACKUP_UPLOAD_CMD, remotePath, backupConfig.format, dataLayout.toString() ], { env: envCopy, preserveEnv: true, ipc: true, onMessage, outputHasTimestamps: true }));
+    // do not use debug for logging child output because it already has timestamps via it's own debug
+    const [error] = await safe(shell.promises.sudo([ BACKUP_UPLOAD_CMD, remotePath, backupConfig.format, dataLayout.toString() ], { env: envCopy, preserveEnv: true, onMessage, logger: process.stdout.write }));
     if (error && (error.code === null /* signal */ || (error.code !== 0 && error.code !== 50))) { // backuptask crashed
         debug(`runBackupUpload: backuptask crashed`, error);
         throw new BoxError(BoxError.INTERNAL_ERROR, 'Backuptask crashed');
diff --git a/src/shell.js b/src/shell.js
index 932c2d0eb..d77f56479 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -113,9 +113,9 @@ function sudo(tag, args, options, callback) {
 
     callback = once(callback); // exit may or may not be called after an 'error'
 
-    const logFunc = options.outputHasTimestamps ? process.stdout.write : debug;
+    const logFunc = options.logger || debug;
 
-    if (options.ipc) {
+    if (options.onMessage) { // enable ipc
         sudoArgs.push('--close-from=4'); // keep the ipc open. requires closefrom_override in sudoers file
         options.stdio = ['pipe', 'pipe', 'pipe', 'ipc'];
     }