diff --git a/index.js b/index.js
index a649a83..2bd2ddd 100644
--- a/index.js
+++ b/index.js
@@ -14,7 +14,7 @@ app.use(express.static('static'));
 
 app.post('/', async function (req, res) {
     let id =  'web:' + createHash('sha256').update(req.ip).digest('base64');
-    id.length = 16;
+    id = id.slice(0,16);
 
     if (!sessions[id]) {
         try {