--- a/testing/web-platform/tests/tools/webdriver/webdriver/protocol.py
+++ b/testing/web-platform/tests/tools/webdriver/webdriver/protocol.py
@@ -1,12 +1,14 @@
 import json
 
 import webdriver
 
+from six import iteritems
+
 
 """WebDriver wire protocol codecs."""
 
 
 class Encoder(json.JSONEncoder):
     def __init__(self, *args, **kwargs):
         kwargs.pop("session")
         super(Encoder, self).__init__(*args, **kwargs)
@@ -34,10 +36,10 @@ class Decoder(json.JSONDecoder):
             return [self.object_hook(x) for x in payload]
         elif isinstance(payload, dict) and webdriver.Element.identifier in payload:
             return webdriver.Element.from_json(payload, self.session)
         elif isinstance(payload, dict) and webdriver.Frame.identifier in payload:
             return webdriver.Frame.from_json(payload, self.session)
         elif isinstance(payload, dict) and webdriver.Window.identifier in payload:
             return webdriver.Window.from_json(payload, self.session)
         elif isinstance(payload, dict):
-            return {k: self.object_hook(v) for k, v in payload.iteritems()}
+            return {k: self.object_hook(v) for k, v in iteritems(payload)}
         return payload