diff --git a/src/socketio/simple_client.py b/src/socketio/simple_client.py
index 3f046b4b..2a29787b 100644
--- a/src/socketio/simple_client.py
+++ b/src/socketio/simple_client.py
@@ -103,7 +103,7 @@ def transport(self):
         The transport is returned as a string and can be one of ``polling``
         and ``websocket``.
         """
-        return self.client.transport if self.client else ''
+        return self.client.transport if self.client else lambda: ''
 
     def emit(self, event, data=None):
         """Emit an event to the server.