diff --git a/swift/obj/updater.py b/swift/obj/updater.py
index 743cf850dc..db38708c4f 100644
--- a/swift/obj/updater.py
+++ b/swift/obj/updater.py
@@ -29,6 +29,7 @@ from swift.common.ring import Ring
 from swift.common.utils import get_logger, renamer, write_pickle, \
     dump_recon_cache, config_true_value, ismount
 from swift.common.daemon import Daemon
+from swift.common.header_key_dict import HeaderKeyDict
 from swift.common.storage_policy import split_policy_string, PolicyError
 from swift.obj.diskfile import get_tmp_dir, ASYNCDIR_BASE
 from swift.common.http import is_success, HTTP_NOT_FOUND, \
@@ -219,7 +220,7 @@ class ObjectUpdater(Daemon):
             update['account'], update['container'])
         obj = '/%s/%s/%s' % \
               (update['account'], update['container'], update['obj'])
-        headers_out = update['headers'].copy()
+        headers_out = HeaderKeyDict(update['headers'])
         headers_out['user-agent'] = 'object-updater %s' % os.getpid()
         headers_out.setdefault('X-Backend-Storage-Policy-Index',
                                str(int(policy)))
diff --git a/test/unit/obj/test_server.py b/test/unit/obj/test_server.py
index 7d03c82c63..116c5d84cc 100644
--- a/test/unit/obj/test_server.py
+++ b/test/unit/obj/test_server.py
@@ -1019,8 +1019,8 @@ class TestObjectController(unittest.TestCase):
         self.assertEqual((node, 99, 'PUT', '/a/c/o'),
                          mock_update.call_args_list[0][0][0:4])
         actual_headers = mock_update.call_args_list[0][0][4]
-        self.assertTrue(
-            actual_headers.pop('user-agent').startswith('object-updater'))
+        # User-Agent is updated.
+        expected_post_headers['User-Agent'] = 'object-updater %s' % os.getpid()
         self.assertDictEqual(expected_post_headers, actual_headers)
         self.assertFalse(
             os.listdir(os.path.join(