diff --git a/python/servo/bootstrap_commands.py b/python/servo/bootstrap_commands.py
index 13db36079ae..bd074b41dec 100644
--- a/python/servo/bootstrap_commands.py
+++ b/python/servo/bootstrap_commands.py
@@ -37,9 +37,10 @@ def download(desc, src, writer, start_byte=0):
     dumb = (os.environ.get("TERM") == "dumb") or (not sys.stdout.isatty())
 
     try:
+        req = urllib2.Request(src)
         if start_byte:
-            src = urllib2.Request(src, headers={'Range': 'bytes={}-'.format(start_byte)})
-        resp = urllib2.urlopen(src)
+            req = urllib2.Request(src, headers={'Range': 'bytes={}-'.format(start_byte)})
+        resp = urllib2.urlopen(req)
 
         fsize = None
         if resp.info().getheader('Content-Length'):
@@ -70,7 +71,7 @@ def download(desc, src, writer, start_byte=0):
                   "Please see https://github.com/servo/servo/#prerequisites")
         sys.exit(1)
     except urllib2.URLError, e:
-        print("Error downloading Rust compiler: " + str(e.reason) + ". The failing URL was: " + src)
+        print("Error downloading Rust compiler: %s. The failing URL was: %s" % (e.reason, src))
         sys.exit(1)
     except KeyboardInterrupt:
         writer.flush()