diff --git a/websocket-sharp/Server/IWebSocketSession.cs b/websocket-sharp/Server/IWebSocketSession.cs
index 4d43652e..296b5bf5 100644
--- a/websocket-sharp/Server/IWebSocketSession.cs
+++ b/websocket-sharp/Server/IWebSocketSession.cs
@@ -4,7 +4,7 @@
  *
  * The MIT License
  *
- * Copyright (c) 2013-2014 sta.blockhead
+ * Copyright (c) 2013-2018 sta.blockhead
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal