diff --git a/templates/book.html b/templates/book.html
index 1d41a42..a2ced76 100644
--- a/templates/book.html
+++ b/templates/book.html
@@ -4,7 +4,7 @@
   <meta charset="UTF-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
-  <title>Document</title>
+  <title>Grafted tree</title>
   <style>
     body, html {
       font-size: 120%;