diff --git a/websocket-sharp/Net/HttpListenerPrefixCollection.cs b/websocket-sharp/Net/HttpListenerPrefixCollection.cs
index 6871a351..cbe062ee 100644
--- a/websocket-sharp/Net/HttpListenerPrefixCollection.cs
+++ b/websocket-sharp/Net/HttpListenerPrefixCollection.cs
@@ -259,8 +259,7 @@ namespace WebSocketSharp.Net
     /// </exception>
     public bool Remove (string uriPrefix)
     {
-      if (_listener.IsDisposed)
-        throw new ObjectDisposedException (_listener.GetType ().ToString ());
+      _listener.CheckDisposed ();
 
       if (uriPrefix == null)
         throw new ArgumentNullException ("uriPrefix");