diff --git a/websocket-sharp/Net/HttpConnection.cs b/websocket-sharp/Net/HttpConnection.cs
index 08ea56b7..5be058dd 100644
--- a/websocket-sharp/Net/HttpConnection.cs
+++ b/websocket-sharp/Net/HttpConnection.cs
@@ -302,9 +302,8 @@ namespace WebSocketSharp.Net
             conn._lastListener = lsnr;
           }
 
-          conn._contextBound = true;
-          if (!lsnr.RegisterContext (conn._context))
-            conn._contextBound = false;
+          if (lsnr.RegisterContext (conn._context))
+            conn._contextBound = true;
 
           return;
         }
diff --git a/websocket-sharp/Net/HttpListener.cs b/websocket-sharp/Net/HttpListener.cs
index 1973ad97..cdcb476c 100644
--- a/websocket-sharp/Net/HttpListener.cs
+++ b/websocket-sharp/Net/HttpListener.cs
@@ -587,6 +587,9 @@ namespace WebSocketSharp.Net
       if (!_listening)
         return false;
 
+      if (!Authenticate (context))
+        return false;
+
       lock (_ctxRegistrySync) {
         if (!_listening)
           return false;
diff --git a/websocket-sharp/Net/HttpListenerAsyncResult.cs b/websocket-sharp/Net/HttpListenerAsyncResult.cs
index 37cdf0b4..a1c73742 100644
--- a/websocket-sharp/Net/HttpListenerAsyncResult.cs
+++ b/websocket-sharp/Net/HttpListenerAsyncResult.cs
@@ -179,18 +179,6 @@ namespace WebSocketSharp.Net
 
     internal void Complete (HttpListenerContext context, bool syncCompleted)
     {
-      try {
-        var lsnr = context.Listener;
-        if (!lsnr.Authenticate (context)) {
-          lsnr.BeginGetContext (this);
-          return;
-        }
-      }
-      catch (Exception ex) {
-        Complete (ex);
-        return;
-      }
-
       _context = context;
       _syncCompleted = syncCompleted;