diff --git a/Gemfile.lock b/Gemfile.lock
index d004ed1b197..f0b9619dcff 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -194,7 +194,7 @@ GEM
     govuk_personalisation (0.16.0)
       plek (>= 1.9.0)
       rails (>= 6, < 8)
-    govuk_publishing_components (41.1.1)
+    govuk_publishing_components (42.0.0)
       govuk_app_config
       govuk_personalisation (>= 0.7.0)
       kramdown
diff --git a/app/views/layouts/application.html.erb b/app/views/layouts/application.html.erb
index 44a026c174e..79b7bbb250a 100644
--- a/app/views/layouts/application.html.erb
+++ b/app/views/layouts/application.html.erb
@@ -26,9 +26,9 @@
     <%= csrf_meta_tags %>
     <%= csp_meta_tag %>
     <%= stylesheet_link_tag "application", :media => "all" %>
-    <%= javascript_include_tag "test-dependencies" if Rails.env.test? %>
+    <%= javascript_include_tag "test-dependencies", type: "module" if Rails.env.test? %>
     <%= javascript_include_tag "es6-components", type: "module" %>
-    <%= javascript_include_tag "application", defer: true %>
+    <%= javascript_include_tag "application", defer: true, type: "module" %>
     <%= yield :head %>
     <% if content_item %>
       <%= render "govuk_publishing_components/components/meta_tags",