diff --git a/System/Event.php b/System/Event.php
index 73a6325a..26926c29 100644
--- a/System/Event.php
+++ b/System/Event.php
@@ -61,7 +61,6 @@ class Event extends BaseObject
 
     const SERVER_HANDSHAKE = 'on handshake';
     const SERVER_MESSAGE = 'on message';
-    const SERVER_CLOSE = 'on close';
     const SERVER_CLIENT_CLOSE = 'SERVER:CLIENT:CLOSE';