diff --git a/flask_socketio/test_client.py b/flask_socketio/test_client.py
index d1a7b060..b22f5c44 100644
--- a/flask_socketio/test_client.py
+++ b/flask_socketio/test_client.py
@@ -24,6 +24,7 @@ def remove_socket(self, socket):
 class TestSocket(object):
     def __init__(self, server):
         self.server = server
+        self.sessid = str(random.random())[2:]
         self.namespace = {}
 
     def __getitem__(self, ns_name):