diff --git a/config.py b/config.py
index bfb88030..d50581f7 100644
--- a/config.py
+++ b/config.py
@@ -64,7 +64,10 @@
 BOT_LOG_FILE = os.path.join(BOT_ROOT, 'errbot.log')
 BOT_LOG_LEVEL = logging.DEBUG
 
-BOT_PREFIX = os.environ.get('BOT_PREFIX', 'corobo ')
+if not os.environ.get('BOT_PREFIX'):
+    raise SystemExit("Environment variable BOT_PREFIX not specified")
+
+BOT_PREFIX = os.environ.get('BOT_PREFIX')
 
 if 'COBOT_PREFIX' in os.environ:
     BOT_PREFIX = os.environ['COBOT_PREFIX']