--- a/testing/web-platform/tests/tools/webdriver/webdriver/transport.py
+++ b/testing/web-platform/tests/tools/webdriver/webdriver/transport.py
@@ -14,16 +14,17 @@ class Response(object):
     body has been read and parsed as appropriate.
     """
 
     def __init__(self, status, body):
         self.status = status
         self.body = body
 
     def __repr__(self):
+        cls_name = self.__class__.__name__
         if self.error:
             return "<%s status=%s error=%s>" % (cls_name, self.status, repr(self.error))
         return "<% status=%s body=%s>" % (cls_name, self.status, json.dumps(self.body))
 
     def __str__(self):
         return json.dumps(self.body, indent=2)
 
     @property