diff --git a/dictation_client/src/App.tsx b/dictation_client/src/App.tsx
index 0f33e23..cfd0d78 100644
--- a/dictation_client/src/App.tsx
+++ b/dictation_client/src/App.tsx
@@ -3,7 +3,7 @@ import { BrowserRouter } from "react-router-dom";
 import { PublicClientApplication } from "@azure/msal-browser";
 import { MsalProvider, useMsal } from "@azure/msal-react";
 import { msalConfig } from "common/msalConfig";
-import { useEffect } from "react";
+import { useEffect, useLayoutEffect } from "react";
 import { useDispatch, useSelector } from "react-redux";
 import globalAxios, { AxiosError, AxiosResponse } from "axios";
 import { clearToken } from "features/auth";
@@ -39,8 +39,9 @@ const App = (): JSX.Element => {
   }, [dispatch, instance]);
 
   // Language読み取り
-  useEffect(() => {
+  useLayoutEffect(() => {
     const language = document.cookie
+      .trim()
       .split(";")
       .map((x) => x.split("="))
       .find((x) => x.length === 2 && x[0] === "language");