diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7f0c7890e9..b76c485cbf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 
 - [#2355: Prevent management pages using "plugin" GOV.UK Frontend views](https://github.com/alphagov/govuk-prototype-kit/pull/2355)
 - [#2358: Suppress Sass warnings for `$legacy` deprecated colour palette](https://github.com/alphagov/govuk-prototype-kit/pull/2358)
+- [#2359: Update application.js to `<script type"module">`](https://github.com/alphagov/govuk-prototype-kit/pull/2359)
 
 ## 13.13.4
 
diff --git a/lib/utils/index.js b/lib/utils/index.js
index 21cc4a3893..1ffa67d668 100644
--- a/lib/utils/index.js
+++ b/lib/utils/index.js
@@ -36,7 +36,10 @@ marked.use({
 
 const scripts = []
 if (existsSync(path.join(projectDir, 'app', 'assets', 'javascripts', 'application.js'))) {
-  scripts.push('/public/javascripts/application.js')
+  scripts.push({
+    src: '/public/javascripts/application.js',
+    type: 'module'
+  })
 }
 if (plugins.legacyGovukFrontendFixesNeeded()) {
   scripts.push('/plugin-assets/govuk-prototype-kit/lib/assets/javascripts/optional/legacy-govuk-frontend-init.js')