diff --git a/source/get-started/index.html.md.erb b/source/get-started/index.html.md.erb
index 455cff2c..f1b62346 100644
--- a/source/get-started/index.html.md.erb
+++ b/source/get-started/index.html.md.erb
@@ -64,10 +64,10 @@ In your live application, we recommend [using an automated task or your build pi
 
 ## 5. Get the JavaScript working
 
-1. Add the following to the top of the `<body>` section of your page template:
+1. Add the following to the top of the `<body class="govuk-template__body">` section of your page template:
 
     ```html
-    <script>document.body.className = ((document.body.className) ? document.body.className + ' js-enabled' : 'js-enabled');</script>
+    <script>document.body.className += ' js-enabled' + ('noModule' in HTMLScriptElement.prototype ? ' govuk-frontend-supported' : '');</script>
     ```
 
 2. Copy the `/node-modules/govuk-frontend/govuk/all.js` file to `<YOUR-JAVASCRIPT-FOLDER>/govuk.js`.
@@ -75,7 +75,7 @@ In your live application, we recommend [using an automated task or your build pi
 3. Import the file before the closing `</body>` tag of your page template, then run the `initAll` function to initialise all the components. For example:
 
     ```html
-    <body>
+    <body class="govuk-template__body">
       ...
       <script src="<YOUR-JAVASCRIPT-FOLDER>/govuk.js"></script>
       <script>
diff --git a/source/importing-css-assets-and-javascript/index.html.md.erb b/source/importing-css-assets-and-javascript/index.html.md.erb
index 0858fad6..5af58598 100644
--- a/source/importing-css-assets-and-javascript/index.html.md.erb
+++ b/source/importing-css-assets-and-javascript/index.html.md.erb
@@ -155,7 +155,7 @@ If you decide to add the JavaScript to your HTML, first either:
 Then import the JavaScript file before the closing `</body>` tag of your HTML page or page template, and run the `initAll` function to initialise all the components.
 
 ```html
-<body>
+<body class="govuk-template__body">
 ...
   <script src="<YOUR-APP>/<YOUR-JS-FILE>.js"></script>
   <script>
@@ -251,7 +251,7 @@ You can unblock inline JavaScript by including the following hash in your CSP:
 %>
 
 ```
-sha256-+6WnXIl4mbFTCARd8N3COQmT3bJJmo32N8q8ZSQAIcU=
+sha256-GUQ5ad8JK5KmEWmROf3LZd9ge94daqNvd8xy9YS1iDw=
 ```
 
 You do not need to make any changes to the HTML.
diff --git a/source/install-using-precompiled-files/index.html.md.erb b/source/install-using-precompiled-files/index.html.md.erb
index ef979dcc..d0961e94 100644
--- a/source/install-using-precompiled-files/index.html.md.erb
+++ b/source/install-using-precompiled-files/index.html.md.erb
@@ -33,7 +33,7 @@ You’ll not be able to:
 
     ```html
     <!DOCTYPE html>
-    <html lang="en" class="govuk-template ">
+    <html lang="en" class="govuk-template">
       <head>
         <title>Example - GOV.UK</title>
         <meta name="viewport" content="width=device-width, initial-scale=1, viewport-fit=cover">
@@ -44,10 +44,8 @@ You’ll not be able to:
           <link rel="stylesheet" href="/stylesheets/govuk-frontend-ie8-<VERSION-NUMBER>.min.css">
         <![endif]-->
       </head>
-      <body class="govuk-template__body ">
-        <script>
-          document.body.className = ((document.body.className) ? document.body.className + ' js-enabled' : 'js-enabled');
-        </script>
+      <body class="govuk-template__body">
+        <script>document.body.className += ' js-enabled' + ('noModule' in HTMLScriptElement.prototype ? ' govuk-frontend-supported' : '');</script>
         <!-- component HTML -->
         <script src="/javascript/govuk-frontend-<VERSION-NUMBER>.min.js"></script>
         <script>
@@ -69,7 +67,3 @@ You’ll not be able to:
 You can now get the full code for page layouts and other components from the [Design System website](https://design-system.service.gov.uk/).
 
 If the accordion does not work, you can [find out more about how to import GOV.UK Frontend's CSS and JavaScript](/importing-css-assets-and-javascript/#import-css-assets-and-javascript).
-
-
-
-
