diff --git a/_config.yml b/_config.yml
index 22e0ce1dc1..98c2864981 100644
--- a/_config.yml
+++ b/_config.yml
@@ -1,7 +1,8 @@
-title: RailsDoc(α)
+title: RailsDoc(β)
 description: Ruby on Rails API Documentation.
 url: https://railsdoc.github.io
 source: src
+target_rails_version: 5.2.3
 plugins:
   - jekyll-redirect-from
   - jekyll-seo-tag
diff --git a/src/_layouts/default.html b/src/_layouts/default.html
index d0ab19c19f..9f64334189 100644
--- a/src/_layouts/default.html
+++ b/src/_layouts/default.html
@@ -3,7 +3,7 @@
 <head>
   <meta charset="UTF-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
-  <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.2.1/css/bootstrap.min.css" integrity="sha384-GJzZqFGwb1QTTN6wy59ffF1BuGJpLSa9DkKMp0DgiMDm4iYMj70gZWKYbI706tWS" crossorigin="anonymous">
+  <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
   <link href="/assets/css/style.css" rel="stylesheet">
   <link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.13.1/styles/github.min.css">
   <link rel="apple-touch-icon" href="icon.png">
@@ -26,8 +26,12 @@
     <form class="w-100" action="/search" method="get">
       <input class="form-control form-control-dark" type="text" placeholder="Search" aria-label="Search" name="q">
     </form>
-    <ul class="navbar-nav px-3">
-      <li class="nav-item text-nowrap">
+
+    <ul class="navbar-nav flex-row ml-md-auto d-none d-md-flex px-1">
+      <li class="nav-item text-nowrap p-2">
+        <a class="nav-link" href="https://github.com/rails/rails/tree/v{{ site.target_rails_version }}">Rails v{{ site.target_rails_version }}</a>
+      </li>
+      <li class="nav-item text-nowrap p-2">
         <a class="nav-link" href="https://github.com/railsdoc/railsdoc.github.io">GitHub</a>
       </li>
     </ul>
