diff --git a/lib/auth.ts b/lib/auth.ts
index a9a76fa..0fe2898 100644
--- a/lib/auth.ts
+++ b/lib/auth.ts
@@ -89,6 +89,7 @@ export const authClient = createAuthClient({
   scheme: 'duooomi',
   fetchOptions: {
     headers: {
+      'Content-Type': 'application/json',
       // x-ownerid: 商户ID（如果后端需要）
       // 如果 MERCHANT_ID 为空，则不添加此 header
       ...(MERCHANT_ID && { 'x-ownerid': MERCHANT_ID }),