diff --git a/packages/firebaseui-core/src/config.ts b/packages/firebaseui-core/src/config.ts
index 235abdfd..d9da7e1a 100644
--- a/packages/firebaseui-core/src/config.ts
+++ b/packages/firebaseui-core/src/config.ts
@@ -59,15 +59,18 @@ export function initializeUI(config: FirebaseUIConfigurationOptions, name: strin
 
   config.translations ??= [];
 
-  // TODO: Is this right?
-  config.translations.push(english);
-
-  const translations = config.translations?.reduce((acc, translation) => {
-    return {
-      ...acc,
-      [translation.locale]: translation.translations,
-    };
-  }, {} as TranslationsConfig);
+  // Map the translations to a TranslationsConfig object.
+  // If no translations are provided, use the English translations as default.
+  const translations = config.translations?.reduce(
+    (acc, translation) => {
+      return {
+        ...acc,
+        [translation.locale]: translation.translations,
+      };
+    },
+    //TODO: Do we always want to include English here?
+    { [english.locale]: english.translations } as TranslationsConfig
+  );
 
   $config.setKey(
     name,
diff --git a/packages/firebaseui-core/tests/unit/translations.test.ts b/packages/firebaseui-core/tests/unit/translations.test.ts
index d7e26ad4..803c73d0 100644
--- a/packages/firebaseui-core/tests/unit/translations.test.ts
+++ b/packages/firebaseui-core/tests/unit/translations.test.ts
@@ -142,4 +142,29 @@ describe('getTranslation', () => {
     const translation = getTranslation(mockUi as any, 'errors', 'userNotFound');
     expect(translation).toBe('No account found with this email address');
   });
+
+  it('should allow custom en-US translation to overwrite the default one', () => {
+    const customEnUs = {
+      locale: 'en-US',
+      translations: {
+        errors: {
+          userNotFound: 'Custom override message',
+        },
+      },
+    };
+
+    const config = {
+      translations: [customEnUs],
+    };
+
+    const result = config.translations.reduce(
+      (acc, t) => ({
+        ...acc,
+        [t.locale]: t.translations,
+      }),
+      { [english.locale]: english.translations }
+    );
+
+    expect(result['en-US'].errors.userNotFound).toBe('Custom override message');
+  });
 });