diff --git a/packages/backend/src/server/web/ClientServerService.ts b/packages/backend/src/server/web/ClientServerService.ts
index e3f35df194..482ff22d29 100644
--- a/packages/backend/src/server/web/ClientServerService.ts
+++ b/packages/backend/src/server/web/ClientServerService.ts
@@ -144,7 +144,9 @@ export class ClientServerService {
 
 		// Authenticate
 		fastify.addHook('onRequest', async (request, reply) => {
-			if (request.url === bullBoardPath || request.url.startsWith(bullBoardPath + '/')) {
+			// %71ueueとかでリクエストされたら困るため
+			const url = decodeURI(request.url);
+			if (url === bullBoardPath || url.startsWith(bullBoardPath + '/')) {
 				const token = request.cookies.token;
 				if (token == null) {
 					reply.code(401);