diff --git a/websocket-sharp/Net/HttpListenerPrefixCollection.cs b/websocket-sharp/Net/HttpListenerPrefixCollection.cs
index 469654ca..6510dcd0 100644
--- a/websocket-sharp/Net/HttpListenerPrefixCollection.cs
+++ b/websocket-sharp/Net/HttpListenerPrefixCollection.cs
@@ -51,8 +51,7 @@ namespace WebSocketSharp.Net
   /// The <see cref="HttpListener"/> instance responds to the request which has
   /// a requested URI that the prefixes most closely match.
   /// </remarks>
-  public class HttpListenerPrefixCollection
-    : ICollection<string>, IEnumerable<string>, IEnumerable
+  public class HttpListenerPrefixCollection : ICollection<string>
   {
     #region Private Fields