diff --git a/lib/py/src/transport/TSocket.py b/lib/py/src/transport/TSocket.py
index e6168e2..e8b43be 100644
--- a/lib/py/src/transport/TSocket.py
+++ b/lib/py/src/transport/TSocket.py
@@ -27,6 +27,8 @@
   def setTimeout(self, ms):
     if (self.handle != None):
       self.handle.settimeout(ms/1000.00)
+    else:
+      raise TTransportException(TTransportException.NOT_OPEN, 'No handle yet in TSocket')
 
   def open(self):
     try: