diff --git a/script/lib/util.py b/script/lib/util.py
index b71e5838be8d..51ca69dc378e 100644
--- a/script/lib/util.py
+++ b/script/lib/util.py
@@ -1,20 +1,27 @@
+#!/usr/bin/env python
+
 import atexit
+import errno
 import shutil
 import tarfile
 import tempfile
 import urllib2
+import os
 
 
-def download(text, url, filename):
-  directory = tempfile.mkdtemp(prefix='atom-shell-')
+def tempdir(prefix=''):
+  directory = tempfile.mkdtemp(prefix=prefix)
   atexit.register(shutil.rmtree, directory)
+  return directory
 
-  web_file = urllib2.urlopen(url)
-  file_size = int(web_file.info().getheaders("Content-Length")[0])
-  downloaded_size = 0
-  block_size = 128
 
-  with open(os.path.join(directory, filename), 'w+') as local_file:
+def download(text, url, path):
+  with open(path, 'w') as local_file:
+    web_file = urllib2.urlopen(url)
+    file_size = int(web_file.info().getheaders("Content-Length")[0])
+    downloaded_size = 0
+    block_size = 128
+
     while True:
       buf = web_file.read(block_size)
       if not buf:
@@ -29,8 +36,6 @@ def download(text, url, filename):
 
     print
 
-  return directory
-
 
 def extract_tarball(tarball_path, member, path):
   with tarfile.open(tarball_path) as tarball:
diff --git a/script/update-node.py b/script/update-node.py
index bfa2aa07492d..caadb3c8ff8c 100755
--- a/script/update-node.py
+++ b/script/update-node.py
@@ -23,12 +23,14 @@ def main():
     return 0
 
   url, filename = get_node_url(args.url, args.version)
-  directory = download('Download node', url, filename)
+  directory = tempdir(prefix='atom-shell-')
+  path = os.path.join(directory, filename)
+  download('Download node', url, path)
 
   if IS_POSIX:
     root_name = 'node-{0}-{1}-x86'.format(args.version, sys.platform)
     member = os.path.join(root_name, 'bin', 'node')
-    extract_tarball(os.path.join(directory, filename), member, directory)
+    extract_tarball(path, member, directory)
     node_path = os.path.join(directory, member)
 
   copy_node(node_path)