diff --git a/packages/localize/src/localize.js b/packages/localize/src/localize.js
index 6ca4d3f06..0df5027b3 100644
--- a/packages/localize/src/localize.js
+++ b/packages/localize/src/localize.js
@@ -3,6 +3,7 @@ import { LocalizeManager } from './LocalizeManager.js';
 // eslint-disable-next-line import/no-mutable-exports
 export let localize = LocalizeManager.getInstance({
   autoLoadOnLocaleChange: true,
+  fallbackLocale: 'en-GB',
 });
 
 export function setLocalize(newLocalize) {
diff --git a/packages/localize/test/localize.test.js b/packages/localize/test/localize.test.js
index 6ad0bb783..b87b77dd8 100644
--- a/packages/localize/test/localize.test.js
+++ b/packages/localize/test/localize.test.js
@@ -38,4 +38,8 @@ describe('localize', () => {
   it('is configured to automatically load namespaces if locale is changed', () => {
     expect(localize._autoLoadOnLocaleChange).to.equal(true);
   });
+
+  it('is configured to fallback to the locale "en-GB"', () => {
+    expect(localize._fallbackLocale).to.equal('en-GB');
+  });
 });