diff --git a/example/src/routes/_layout.svelte b/example/src/routes/_layout.svelte
index 36f972f..7bf9195 100644
--- a/example/src/routes/_layout.svelte
+++ b/example/src/routes/_layout.svelte
@@ -3,7 +3,7 @@
 
   export async function preload() {
     return setInitialLocale({
-      fallback: 'en-US',
+      fallback: 'en',
       // navigator: true,
       search: 'lang'
     })
diff --git a/src/client/stores/locale.ts b/src/client/stores/locale.ts
index c924da4..3e3ff41 100644
--- a/src/client/stores/locale.ts
+++ b/src/client/stores/locale.ts
@@ -25,7 +25,7 @@ export function isFallbackLocaleOf(localeA: string, localeB: string) {
 export function getFallbackOf(locale: string) {
   const index = locale.lastIndexOf('-')
   if (index > 0) return locale.slice(0, index)
-  if (fallback && !isFallbackLocaleOf(locale, fallback)) return fallback
+  if (fallback && !isFallbackLocaleOf(fallback, locale)) return fallback
   return null
 }
 
@@ -34,7 +34,7 @@ export function getFallbacksOf(locale: string): string[] {
     .split('-')
     .map((_, i, arr) => arr.slice(0, i + 1).join('-'))
 
-  if (fallback != null && !isFallbackLocaleOf(locale, fallback)) {
+  if (fallback != null && !isFallbackLocaleOf(fallback, locale)) {
     return locales.concat(getFallbacksOf(fallback))
   }
   return locales