diff --git a/packages/web/common/system/nextjs.ts b/packages/web/common/system/nextjs.ts
index 60b0c7bac..54a4bb9c4 100644
--- a/packages/web/common/system/nextjs.ts
+++ b/packages/web/common/system/nextjs.ts
@@ -6,7 +6,7 @@ export const serviceSideProps = async (content: any, ns: I18nNsType = []) => {
   const extraLng = content.req?.cookies?.NEXT_LOCALE ? undefined : content.locales;
 
   // Device size
-  const deviceSize = content.req?.cookies?.NEXT_DEVICE_SIZE || 'pc';
+  const deviceSize = content.req?.cookies?.NEXT_DEVICE_SIZE || null;
 
   return {
     ...(await serverSideTranslations(lang, ['common', ...ns], null, extraLng)),
diff --git a/packages/web/context/useSystem.tsx b/packages/web/context/useSystem.tsx
index 48268e595..9462b484c 100644
--- a/packages/web/context/useSystem.tsx
+++ b/packages/web/context/useSystem.tsx
@@ -23,7 +23,7 @@ const SystemStoreContextProvider = ({
   device
 }: {
   children: ReactNode;
-  device?: 'pc' | 'mobile';
+  device?: 'pc' | 'mobile' | null;
 }) => {
   const [isPc] = useMediaQuery('(min-width: 900px)');