diff --git a/apps/frontend/src/lib/i18n/index.ts b/apps/frontend/src/lib/i18n/index.ts
index 4fb4030d..50ea2f1c 100644
--- a/apps/frontend/src/lib/i18n/index.ts
+++ b/apps/frontend/src/lib/i18n/index.ts
@@ -16,8 +16,8 @@ export const languageNames: Record<SupportedLanguage, string> = {
 /**
  * Initialize i18next with the given language or auto-detect
  */
-export function initI18n(initialLanguage?: SupportedLanguage) {
-  i18next.use(LanguageDetector).init({
+export async function initI18n(initialLanguage?: SupportedLanguage) {
+  await i18next.use(LanguageDetector).init({
     resources: {
       en: { translation: en },
       de: { translation: de },
diff --git a/apps/frontend/src/lib/stores/locale.ts b/apps/frontend/src/lib/stores/locale.ts
index 1a64c93e..644282e7 100644
--- a/apps/frontend/src/lib/stores/locale.ts
+++ b/apps/frontend/src/lib/stores/locale.ts
@@ -32,7 +32,7 @@ function createLocaleStore() {
      */
     initialize: async (userLanguage?: SupportedLanguage) => {
       // Initialize i18next with user's preference or auto-detect
-      initI18n(userLanguage);
+      await initI18n(userLanguage);
       const detectedLang = getCurrentLanguage();
 
       // Update document lang attribute
diff --git a/apps/frontend/src/routes/+layout.svelte b/apps/frontend/src/routes/+layout.svelte
index a4bed241..2298d217 100644
--- a/apps/frontend/src/routes/+layout.svelte
+++ b/apps/frontend/src/routes/+layout.svelte
@@ -19,7 +19,7 @@ import {
   userPreferences,
 } from '$lib/stores/auth';
 import { circles } from '$lib/stores/circles';
-import { locale } from '$lib/stores/locale';
+import { isLocaleInitialized, locale } from '$lib/stores/locale';
 
 interface Props {
   children: Snippet;
@@ -52,7 +52,7 @@ $effect(() => {
 // Sync language when user preferences change (e.g., after login)
 $effect(() => {
   const prefs = $userPreferences;
-  if (prefs?.language && prefs.language !== locale.getLanguage()) {
+  if ($isLocaleInitialized && prefs?.language && prefs.language !== locale.getLanguage()) {
     locale.setLanguage(prefs.language as SupportedLanguage);
   }
 });