diff --git a/src/boot/i18n.ts b/src/boot/i18n.ts
index 647f3d10..9e2cda0d 100644
--- a/src/boot/i18n.ts
+++ b/src/boot/i18n.ts
@@ -2,6 +2,7 @@ import { defineBoot } from '#q-app/wrappers';
 import { createI18n } from 'vue-i18n';
 
 import messages from 'src/i18n';
+import { Lang } from 'src/utils/ui';
 
 export type MessageLanguages = keyof typeof messages;
 // Type-define 'eng' as the master schema for the resource
@@ -26,7 +27,7 @@ export const i18n = createI18n<
   MessageLanguages,
   false
 >({
-  locale: 'en-US',
+  locale: Lang.Thai,
   legacy: false,
   messages,
 });