diff --git a/tryton/rpc.py b/tryton/rpc.py
index f4e1fbf8a8..5829fd74dc 100644
--- a/tryton/rpc.py
+++ b/tryton/rpc.py
@@ -82,7 +82,6 @@ def login(username, password, host, port, database):
         finally:
             _SEMAPHORE.release()
     except socket.error:
-        _SOCK = None
         _USER = 0
         _SESSION = ''
         return -1