diff --git a/pnut-bridge.py b/pnut-bridge.py
index 0506060..c313805 100644
--- a/pnut-bridge.py
+++ b/pnut-bridge.py
@@ -185,7 +185,8 @@ class ChannelMonitor(threading.Thread):
         logging.info("-- Starting channel monitor --")
         app.app_context().push()
         rooms = MatrixRoom2.query.all()
-        self.txId = int(rooms[0].pnut_since)
+        if rooms:
+            self.txId = int(rooms[0].pnut_since)
         while not _shutdown.isSet():
             rooms = MatrixRoom2.query.all()
             for r in rooms: