diff --git a/scripts/update_device.py b/scripts/update_device.py
index 1cd4b6a..756d443 100755
--- a/scripts/update_device.py
+++ b/scripts/update_device.py
@@ -17,6 +17,7 @@
 
 """Send an A/B update to an Android device over adb."""
 
+from __future__ import print_function
 from __future__ import absolute_import
 
 import argparse
@@ -305,6 +306,7 @@
     logging.info('Server Terminated')
 
   def StopServer(self):
+    self._httpd.shutdown()
     self._httpd.socket.close()
 
 
@@ -318,13 +320,13 @@
   """Return the command to run to start the update in the Android device."""
   ota = AndroidOTAPackage(ota_filename, secondary)
   headers = ota.properties
-  headers += 'USER_AGENT=Dalvik (something, something)\n'
-  headers += 'NETWORK_ID=0\n'
-  headers += extra_headers
+  headers += b'USER_AGENT=Dalvik (something, something)\n'
+  headers += b'NETWORK_ID=0\n'
+  headers += extra_headers.encode()
 
   return ['update_engine_client', '--update', '--follow',
           '--payload=%s' % payload_url, '--offset=%d' % ota.offset,
-          '--size=%d' % ota.size, '--headers="%s"' % headers]
+          '--size=%d' % ota.size, '--headers="%s"' % headers.decode()]
 
 
 def OmahaUpdateCommand(omaha_url):