diff --git a/shadowsocks-csharp/Util/Sockets/WrappedSocket.cs b/shadowsocks-csharp/Util/Sockets/WrappedSocket.cs
index 2f3aa4719..0ef07912d 100644
--- a/shadowsocks-csharp/Util/Sockets/WrappedSocket.cs
+++ b/shadowsocks-csharp/Util/Sockets/WrappedSocket.cs
@@ -42,7 +42,10 @@ public void BeginConnect(EndPoint remoteEP, AsyncCallback callback, object state
             arg.Completed += OnTcpConnectCompleted;
             arg.UserToken = new TcpUserToken(callback, state);
 
-            Socket.ConnectAsync(SocketType.Stream, ProtocolType.Tcp, arg);
+            if(!Socket.ConnectAsync(SocketType.Stream, ProtocolType.Tcp, arg))
+            {
+                OnTcpConnectCompleted(this, arg);
+            }
         }
 
         private class FakeAsyncResult : IAsyncResult