diff --git a/apns_python/__init__.py b/apns_python/__init__.py
index 998b1d3..62e0b9e 100644
--- a/apns_python/__init__.py
+++ b/apns_python/__init__.py
@@ -17,5 +17,5 @@
 use them with their module prefix like notification.Alert
 """
 
-from notification import Alert, APS, Payload, Headers
-from client import Client
+from .notification import Alert, APS, Payload, Headers
+from .client import Client
diff --git a/apns_python/client.py b/apns_python/client.py
index ff13071..b4f8d9d 100644
--- a/apns_python/client.py
+++ b/apns_python/client.py
@@ -12,8 +12,8 @@ class Client(object):
     apns_path = '/3/device/'
 
     def __init__(
-            self, push_mode='dev', secure=True, cert_location=None,
-            cert_password=None, conn_timeout, request_timeout):
+            self, push_mode='dev', secure=True, cert_chain_location=None, cert_location=None,
+            cert_password=None):
         if push_mode == 'dev':
             self.apns_host = Client.dev_apns_host
         elif push_mode == 'prd':
@@ -23,14 +23,13 @@ def __init__(
                 'The push_mode param must be "dev" or "prd", not {0}'.format(
                     push_mode))
             raise ValueError(err_msg)
-        if cert_location:
-            ssl_context_obj = tls.init_context(
+        if cert_location and cert_chain_location:
+            ssl_context_obj = tls.init_context(cert_path=cert_chain_location,
                 cert=cert_location, cert_password=cert_password)
         else:
             ssl_context_obj = None
         self.conn = HTTP20Connection(
-            self.apns_host, secure=secure, ssl_context=ssl_context_obj,
-            timeout=(conn_timeout, request_timeout))
+            self.apns_host, secure=secure, ssl_context=ssl_context_obj)
 
     def send(self, device_token, headers, payload):
         """Send the notification to apns.
diff --git a/apns_python/notification.py b/apns_python/notification.py
index 8c9379b..57b42b8 100644
--- a/apns_python/notification.py
+++ b/apns_python/notification.py
@@ -12,7 +12,7 @@ def __init__(self, custom_fields={}, **apn_args):
 
     def update_keys(self, apn_args, msg_obj_keys):
         """Transform the input keys with '_' to apns format with '-'."""
-        for k, v in apn_args.iteritems():
+        for k, v in apn_args.items():
             formated_k = k.replace('_', '-')
             if formated_k in msg_obj_keys:
                 del apn_args[k]