diff --git a/userfront/lib/core/services/auth_proxy_service.dart b/userfront/lib/core/services/auth_proxy_service.dart
index 8d0f5958..50658953 100644
--- a/userfront/lib/core/services/auth_proxy_service.dart
+++ b/userfront/lib/core/services/auth_proxy_service.dart
@@ -16,7 +16,7 @@ class AuthProxyService {
   static String get _baseUrl {
     final rawUrl = _envOrDefault('BACKEND_URL', 'https://sso.hmac.kr');
     // 배포 환경에서 $ 기호나 공백이 섞여 들어오는 경우를 방지하기 위해 정제합니다.
-    return rawUrl.replaceAll('$', '').trim().replaceAll(RegExp(r'/$'), '');
+    return rawUrl.replaceAll(r'$', '').trim().replaceAll(RegExp(r'/$'), '');
   }
   static bool get _isProd {
     final env = _envOrDefault('APP_ENV', 'dev').toLowerCase();