diff --git a/test/mosq_test.py b/test/mosq_test.py
index 45ed750e..5cbc671c 100644
--- a/test/mosq_test.py
+++ b/test/mosq_test.py
@@ -250,7 +250,7 @@ def to_string(packet):
         # Reserved
         return "0xF0"
 
-def gen_connect(client_id, clean_session=True, keepalive=60, username=None, password=None, will_topic=None, will_qos=0, will_retain=False, will_payload="", proto_ver=3):
+def gen_connect(client_id, clean_session=True, keepalive=60, username=None, password=None, will_topic=None, will_qos=0, will_retain=False, will_payload="", proto_ver=4):
     if (proto_ver&0x7F) == 3 or proto_ver == 0:
         remaining_length = 12
     elif (proto_ver&0x7F) == 4: