diff --git a/src/app/layout.tsx b/src/app/layout.tsx
index 66958a0..70b22a5 100644
--- a/src/app/layout.tsx
+++ b/src/app/layout.tsx
@@ -16,7 +16,7 @@ export default function RootLayout({
   children: React.ReactNode;
 }>) {
   return (
-    <html lang='en'>
+    <html lang='ja'>
       <body className={inter.className}>{children}</body>
     </html>
   );
