diff --git a/websocket-sharp/Net/HttpListenerAsyncResult.cs b/websocket-sharp/Net/HttpListenerAsyncResult.cs
index a1c73742..3b759560 100644
--- a/websocket-sharp/Net/HttpListenerAsyncResult.cs
+++ b/websocket-sharp/Net/HttpListenerAsyncResult.cs
@@ -72,6 +72,7 @@ namespace WebSocketSharp.Net
     {
       _callback = callback;
       _state = state;
+
       _sync = new object ();
     }