diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9f1071b3..f290e630 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,7 +16,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Removed single `content` property in hero components in favour of separate fields (i.e. `title`, `text`/`body`)
 - Nested unordered lists use the same marker
-- The Cookie library is now a singleton
+- The cookie library is now a singleton
+- The analytics library instance is saved to the window object
 - Improved typeface definitions and includes
 
 ### Deprecated
diff --git a/src/nationalarchives/analytics.mjs b/src/nationalarchives/analytics.mjs
index d9d01bc1..7cff9d9d 100644
--- a/src/nationalarchives/analytics.mjs
+++ b/src/nationalarchives/analytics.mjs
@@ -242,8 +242,8 @@ class GA4 extends EventTracker {
   gTagId;
 
   constructor(options = {}) {
-    if (GA4._instance) {
-      return GA4._instance;
+    if (window.TNAFrontendAnalytics) {
+      return window.TNAFrontendAnalytics;
     }
     const {
       id = "",
@@ -252,7 +252,7 @@ class GA4 extends EventTracker {
       addTrackingCode = true,
     } = options;
     super({ prefix, addTrackingCode });
-    GA4._instance = this;
+    window.TNAFrontendAnalytics = this;
     this.gTagId = id;
     this.ga4Disable = `ga-disable-${this.gTagId}`;
     window.dataLayer = window.dataLayer || [];
@@ -264,7 +264,7 @@ class GA4 extends EventTracker {
   }
 
   destroy() {
-    GA4._instance = null;
+    window.TNAFrontendAnalytics = null;
   }
 
   /** @protected */
diff --git a/test/analytics.test.js b/test/analytics.test.js
index 36d4b3a1..42649d60 100644
--- a/test/analytics.test.js
+++ b/test/analytics.test.js
@@ -73,7 +73,7 @@ describe("With consent", () => {
     document.clearAllCookies();
     document.cookie =
       "cookies_policy=%7B%22usage%22%3Atrue%2C%22settings%22%3Atrue%2C%22essential%22%3Atrue%7D";
-    GA4._instance = null;
+    window.TNAFrontendAnalytics = null;
     document.head.innerHTML = "";
     document.body.innerHTML = "";