diff --git a/hbmqtt/mqtt/connect.py b/hbmqtt/mqtt/connect.py
index 3359482..6b16e26 100644
--- a/hbmqtt/mqtt/connect.py
+++ b/hbmqtt/mqtt/connect.py
@@ -7,6 +7,7 @@ from hbmqtt.codecs import bytes_to_int, decode_data_with_length, decode_string,
 from hbmqtt.mqtt.packet import MQTTPacket, MQTTFixedHeader, CONNECT, MQTTVariableHeader, MQTTPayload
 from hbmqtt.errors import HBMQTTException, NoDataException
 from hbmqtt.adapters import ReaderAdapter
+from hbmqtt.utils import gen_client_id
 
 
 class ConnectVariableHeader(MQTTVariableHeader):
@@ -161,6 +162,9 @@ class ConnectPayload(MQTTPayload):
         except NoDataException:
             payload.client_id = None
 
+        if (payload.client_id is None or payload.client_id == ""):
+            payload.client_id=gen_client_id();
+
         # Read will topic, username and password
         if variable_header.will_flag:
             try:
diff --git a/tests/test_client.py b/tests/test_client.py
index bb3456b..978f8a0 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -103,7 +103,7 @@ class MQTTClientTest(unittest.TestCase):
                 broker = Broker(broker_config, plugin_namespace="hbmqtt.test.plugins")
                 yield from broker.start()
                 client = MQTTClient()
-                yield from client.connect('ws://localhost:8081/')
+                yield from client.connect('ws://localhost:8080/')
                 self.assertIsNotNone(client.session)
                 yield from client.disconnect()
                 yield from broker.shutdown()