diff --git a/websocket-sharp/Server/WebSocketBehavior.cs b/websocket-sharp/Server/WebSocketBehavior.cs
index 71febd7f..3bdb4e3c 100644
--- a/websocket-sharp/Server/WebSocketBehavior.cs
+++ b/websocket-sharp/Server/WebSocketBehavior.cs
@@ -351,7 +351,7 @@ namespace WebSocketSharp.Server
     internal void Start (WebSocketContext context, WebSocketSessionManager sessions)
     {
       if (_websocket != null) {
-        _websocket.Log.Error ("This session has already been started.");
+        _websocket.Log.Error ("A session instance cannot be reused.");
         context.WebSocket.Close (HttpStatusCode.ServiceUnavailable);
 
         return;