diff --git a/websocket-sharp/Server/HttpServer.cs b/websocket-sharp/Server/HttpServer.cs
index ce1df004..604bd182 100644
--- a/websocket-sharp/Server/HttpServer.cs
+++ b/websocket-sharp/Server/HttpServer.cs
@@ -550,15 +550,9 @@ namespace WebSocketSharp.Server
       }
 
       set {
-        string msg;
-
-        if (!canSet (out msg)) {
-          _log.Warn (msg);
-
-          return;
-        }
-
         lock (_sync) {
+          string msg;
+
           if (!canSet (out msg)) {
             _log.Warn (msg);