diff --git a/nemubot/bot.py b/nemubot/bot.py
index 0889ca1..d83f22e 100644
--- a/nemubot/bot.py
+++ b/nemubot/bot.py
@@ -48,6 +48,7 @@ class Bot(threading.Thread):
         logger.info("Initiate nemubot v%s", __version__)
 
         self.verbosity = verbosity
+        self.stop = None
 
         # External IP for accessing this bot
         import ipaddress