diff --git a/src/javascripts/components/back-to-top.mjs b/src/javascripts/components/back-to-top.mjs
index 00d8cecbe4..b5f6b9ca78 100644
--- a/src/javascripts/components/back-to-top.mjs
+++ b/src/javascripts/components/back-to-top.mjs
@@ -6,7 +6,10 @@ class BackToTop {
    * @param {Element} $module - HTML element
    */
   constructor($module) {
-    if (!($module instanceof HTMLElement)) {
+    if (
+      !($module instanceof HTMLElement) ||
+      !document.body.classList.contains('govuk-frontend-supported')
+    ) {
       return this
     }
 
diff --git a/src/javascripts/components/cookie-banner.mjs b/src/javascripts/components/cookie-banner.mjs
index 3eccb93bf5..cb98de533c 100644
--- a/src/javascripts/components/cookie-banner.mjs
+++ b/src/javascripts/components/cookie-banner.mjs
@@ -17,6 +17,7 @@ class CookieBanner {
   constructor($module) {
     if (
       !($module instanceof HTMLElement) ||
+      !document.body.classList.contains('govuk-frontend-supported') ||
       // Exit if we're on the cookies page to avoid circular journeys
       this.onCookiesPage()
     ) {
diff --git a/src/javascripts/components/cookies-page.mjs b/src/javascripts/components/cookies-page.mjs
index 17a4c0e0c7..d7479b1c20 100644
--- a/src/javascripts/components/cookies-page.mjs
+++ b/src/javascripts/components/cookies-page.mjs
@@ -8,7 +8,10 @@ class CookiesPage {
    * @param {Element} $module - HTML element
    */
   constructor($module) {
-    if (!($module instanceof HTMLElement)) {
+    if (
+      !($module instanceof HTMLElement) ||
+      !document.body.classList.contains('govuk-frontend-supported')
+    ) {
       return this
     }
 
diff --git a/src/javascripts/components/copy.mjs b/src/javascripts/components/copy.mjs
index c08534c802..7dd78ed5ed 100644
--- a/src/javascripts/components/copy.mjs
+++ b/src/javascripts/components/copy.mjs
@@ -8,7 +8,10 @@ class Copy {
    * @param {Element} $module - HTML element
    */
   constructor($module) {
-    if (!($module instanceof HTMLElement)) {
+    if (
+      !($module instanceof HTMLElement) ||
+      !document.body.classList.contains('govuk-frontend-supported')
+    ) {
       return this
     }
 
diff --git a/src/javascripts/components/example-page.mjs b/src/javascripts/components/example-page.mjs
index c4f63a4e0b..e03269866f 100644
--- a/src/javascripts/components/example-page.mjs
+++ b/src/javascripts/components/example-page.mjs
@@ -6,7 +6,10 @@ class ExamplePage {
    * @param {Document} $module - HTML document
    */
   constructor($module) {
-    if (!($module instanceof Document)) {
+    if (
+      !($module instanceof Document) ||
+      !document.body.classList.contains('govuk-frontend-supported')
+    ) {
       return this
     }
 
diff --git a/src/javascripts/components/example.mjs b/src/javascripts/components/example.mjs
index f780dd3d16..4d38854224 100644
--- a/src/javascripts/components/example.mjs
+++ b/src/javascripts/components/example.mjs
@@ -13,7 +13,10 @@ class Example {
    * @param {Element} $module - HTML element
    */
   constructor($module) {
-    if (!($module instanceof HTMLIFrameElement)) {
+    if (
+      !($module instanceof HTMLIFrameElement) ||
+      !document.body.classList.contains('govuk-frontend-supported')
+    ) {
       return
     }
 
diff --git a/src/javascripts/components/navigation.mjs b/src/javascripts/components/navigation.mjs
index 121014dc65..8309495e2d 100644
--- a/src/javascripts/components/navigation.mjs
+++ b/src/javascripts/components/navigation.mjs
@@ -12,7 +12,10 @@ class Navigation {
    * @param {Document} $module - HTML document
    */
   constructor($module) {
-    if (!($module instanceof Document)) {
+    if (
+      !($module instanceof Document) ||
+      !document.body.classList.contains('govuk-frontend-supported')
+    ) {
       return this
     }
 
diff --git a/src/javascripts/components/search.mjs b/src/javascripts/components/search.mjs
index f2c954d04f..f72224d73e 100644
--- a/src/javascripts/components/search.mjs
+++ b/src/javascripts/components/search.mjs
@@ -41,7 +41,10 @@ class Search {
    * @param {Element} $module - HTML element
    */
   constructor($module) {
-    if (!($module instanceof HTMLElement)) {
+    if (
+      !($module instanceof HTMLElement) ||
+      !document.body.classList.contains('govuk-frontend-supported')
+    ) {
       return this
     }
 
diff --git a/src/javascripts/components/tabs.mjs b/src/javascripts/components/tabs.mjs
index c388acd407..8df1593c30 100644
--- a/src/javascripts/components/tabs.mjs
+++ b/src/javascripts/components/tabs.mjs
@@ -13,7 +13,10 @@ class AppTabs {
    * @param {Element} $module - HTML element
    */
   constructor($module) {
-    if (!($module instanceof HTMLElement)) {
+    if (
+      !($module instanceof HTMLElement) ||
+      !document.body.classList.contains('govuk-frontend-supported')
+    ) {
       return this
     }