diff --git a/websocket-sharp/Net/HttpListenerAsyncResult.cs b/websocket-sharp/Net/HttpListenerAsyncResult.cs
index 17b283a5..909f15bf 100644
--- a/websocket-sharp/Net/HttpListenerAsyncResult.cs
+++ b/websocket-sharp/Net/HttpListenerAsyncResult.cs
@@ -108,34 +108,30 @@ namespace WebSocketSharp.Net
 
     #region Private Methods
 
-    private static bool authenticate (HttpListenerContext context)
+    private static bool authenticate (
+      HttpListenerContext context,
+      AuthenticationSchemes scheme,
+      string realm,
+      Func<IIdentity, NetworkCredential> credentialsFinder)
     {
-      var listener = context.Listener;
-      var schm = listener.SelectAuthenticationScheme (context);
-      if (schm == AuthenticationSchemes.Anonymous)
-        return true;
-
-      if (schm == AuthenticationSchemes.None) {
+      if (scheme == AuthenticationSchemes.None) {
         context.Response.Close (HttpStatusCode.Forbidden);
         return false;
       }
 
       var req = context.Request;
-      var realm = listener.Realm;
       var user = HttpUtility.CreateUser (
-        req.Headers["Authorization"], schm, realm, req.HttpMethod, listener.UserCredentialsFinder);
+        req.Headers["Authorization"], scheme, realm, req.HttpMethod, credentialsFinder);
 
       if (user != null && user.Identity.IsAuthenticated) {
         context.User = user;
-        req.IsAuthenticated = true;
-
         return true;
       }
 
-      if (schm == AuthenticationSchemes.Basic)
+      if (scheme == AuthenticationSchemes.Basic)
         context.Response.CloseWithAuthChallenge (
           AuthenticationChallenge.CreateBasicChallenge (realm).ToBasicString ());
-      else if (schm == AuthenticationSchemes.Digest)
+      else if (scheme == AuthenticationSchemes.Digest)
         context.Response.CloseWithAuthChallenge (
           AuthenticationChallenge.CreateDigestChallenge (realm).ToDigestString ());
       else
@@ -186,8 +182,11 @@ namespace WebSocketSharp.Net
 
     internal void Complete (HttpListenerContext context, bool syncCompleted)
     {
-      if (!authenticate (context)) {
-        context.Listener.BeginGetContext (this);
+      var listener = context.Listener;
+      var schm = listener.SelectAuthenticationScheme (context);
+      if (schm != AuthenticationSchemes.Anonymous &&
+          !authenticate (context, schm, listener.Realm, listener.UserCredentialsFinder)) {
+        listener.BeginGetContext (this);
         return;
       }
 
diff --git a/websocket-sharp/Net/HttpListenerRequest.cs b/websocket-sharp/Net/HttpListenerRequest.cs
index 12d1ad88..383a1151 100644
--- a/websocket-sharp/Net/HttpListenerRequest.cs
+++ b/websocket-sharp/Net/HttpListenerRequest.cs
@@ -59,7 +59,6 @@ namespace WebSocketSharp.Net
 
     private static readonly byte[] _100continue;
     private string[]               _acceptTypes;
-    private bool                   _authenticated;
     private bool                   _chunked;
     private Encoding               _contentEncoding;
     private long                   _contentLength;
@@ -242,11 +241,7 @@ namespace WebSocketSharp.Net
     /// </value>
     public bool IsAuthenticated {
       get {
-        return _authenticated;
-      }
-
-      internal set {
-        _authenticated = value;
+        return _context.User != null;
       }
     }
 
diff --git a/websocket-sharp/Net/WebSockets/HttpListenerWebSocketContext.cs b/websocket-sharp/Net/WebSockets/HttpListenerWebSocketContext.cs
index 23bff44a..f39c3b55 100644
--- a/websocket-sharp/Net/WebSockets/HttpListenerWebSocketContext.cs
+++ b/websocket-sharp/Net/WebSockets/HttpListenerWebSocketContext.cs
@@ -114,7 +114,7 @@ namespace WebSocketSharp.Net.WebSockets
     /// </value>
     public override bool IsAuthenticated {
       get {
-        return _context.Request.IsAuthenticated;
+        return _context.User != null;
       }
     }
 
@@ -257,7 +257,7 @@ namespace WebSocketSharp.Net.WebSockets
     /// Gets the client information (identity, authentication, and security roles).
     /// </summary>
     /// <value>
-    /// A <see cref="IPrincipal"/> that represents the client information.
+    /// A <see cref="IPrincipal"/> instance that represents the client information.
     /// </value>
     public override IPrincipal User {
       get {
diff --git a/websocket-sharp/Net/WebSockets/WebSocketContext.cs b/websocket-sharp/Net/WebSockets/WebSocketContext.cs
index c6424d8b..5f88e709 100644
--- a/websocket-sharp/Net/WebSockets/WebSocketContext.cs
+++ b/websocket-sharp/Net/WebSockets/WebSocketContext.cs
@@ -182,7 +182,7 @@ namespace WebSocketSharp.Net.WebSockets
     /// Gets the client information (identity, authentication, and security roles).
     /// </summary>
     /// <value>
-    /// A <see cref="IPrincipal"/> that represents the client information.
+    /// A <see cref="IPrincipal"/> instance that represents the client information.
     /// </value>
     public abstract IPrincipal User { get; }