diff --git a/src/backups.js b/src/backups.js
index 50f393577..c6f5d08f5 100644
--- a/src/backups.js
+++ b/src/backups.js
@@ -856,7 +856,7 @@ function runBackupUpload(uploadConfig, progressCallback, callback) {
 
     let result = ''; // the script communicates error result as a string
 
-    shell.sudo(`backup-${backupId}`, [ BACKUP_UPLOAD_CMD, backupId, format, dataLayout.toString() ], { preserveEnv: true, ipc: true }, function (error) {
+    shell.sudo(`backup-${backupId}`, [ BACKUP_UPLOAD_CMD, backupId, format, dataLayout.toString() ], { preserveEnv: true, ipc: true, nice: 15 }, function (error) {
         if (error && (error.code === null /* signal */ || (error.code !== 0 && error.code !== 50))) { // backuptask crashed
             return callback(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 3bb8aa5ae..81342e465 100644
--- a/src/shell.js
+++ b/src/shell.js
@@ -13,7 +13,8 @@ var assert = require('assert'),
     once = require('once'),
     util = require('util');
 
-var SUDO = '/usr/bin/sudo';
+const SUDO = '/usr/bin/sudo';
+const NICE = '/usr/bin/nice';
 
 function exec(tag, cmd, callback) {
     assert.strictEqual(typeof tag, 'string');
@@ -39,11 +40,16 @@ function spawn(tag, file, args, options, callback) {
 
     callback = once(callback); // exit may or may not be called after an 'error'
 
-    debug(tag + ' spawn: %s %s', file, args.join(' '));
-
     if (options.ipc) options.stdio = ['pipe', 'pipe', 'pipe', 'ipc'];
 
-    var cp = child_process.spawn(file, args, options);
+    if (options.nice) {
+        args = ['-n', options.nice, file].concat(args);
+        file = NICE;
+    }
+
+    debug(tag + ' spawn: %s %s', file, args.join(' '));
+    const cp = child_process.spawn(file, args, options);
+
     if (options.logStream) {
         cp.stdout.pipe(options.logStream);
         cp.stderr.pipe(options.logStream);