diff --git a/websocket-sharp/Net/HttpListener.cs b/websocket-sharp/Net/HttpListener.cs
index 1966c57f..a5a7448f 100644
--- a/websocket-sharp/Net/HttpListener.cs
+++ b/websocket-sharp/Net/HttpListener.cs
@@ -582,11 +582,10 @@ namespace WebSocketSharp.Net
         _connections.Remove (connection);
     }
 
-    internal AuthenticationSchemes SelectAuthenticationScheme (HttpListenerContext context)
+    internal AuthenticationSchemes SelectAuthenticationScheme (HttpListenerRequest request)
     {
-      return AuthenticationSchemeSelector != null
-             ? AuthenticationSchemeSelector (context.Request)
-             : _authSchemes;
+      var selector = _authSchemeSelector;
+      return selector != null ? selector (request) : _authSchemes;
     }
 
     internal void UnregisterContext (HttpListenerContext context)
diff --git a/websocket-sharp/Net/HttpListenerContext.cs b/websocket-sharp/Net/HttpListenerContext.cs
index 397c2db0..b0a40a9e 100644
--- a/websocket-sharp/Net/HttpListenerContext.cs
+++ b/websocket-sharp/Net/HttpListenerContext.cs
@@ -170,7 +170,7 @@ namespace WebSocketSharp.Net
 
     internal bool Authenticate ()
     {
-      var schm = _listener.SelectAuthenticationScheme (this);
+      var schm = _listener.SelectAuthenticationScheme (_request);
       if (schm == AuthenticationSchemes.Anonymous)
         return true;