diff --git a/websocket-sharp/Net/Cookie.cs b/websocket-sharp/Net/Cookie.cs
index 785300c3..1c5a4bf2 100644
--- a/websocket-sharp/Net/Cookie.cs
+++ b/websocket-sharp/Net/Cookie.cs
@@ -870,6 +870,16 @@ namespace WebSocketSharp.Net
              && _version == cookie._version;
     }
 
+    internal bool EqualsWithoutValueAndVersion (Cookie cookie)
+    {
+      var caseSensitive = StringComparison.InvariantCulture;
+      var caseInsensitive = StringComparison.InvariantCultureIgnoreCase;
+
+      return _name.Equals (cookie._name, caseInsensitive)
+             && _path.Equals (cookie._path, caseSensitive)
+             && _domain.Equals (cookie._domain, caseInsensitive);
+    }
+
     internal string ToRequestString (Uri uri)
     {
       if (_name.Length == 0)