diff --git a/external-library/mywust b/external-library/mywust
index 5fd5099..c13aa2f 160000
--- a/external-library/mywust
+++ b/external-library/mywust
@@ -1 +1 @@
-Subproject commit 5fd50991814322760c7f4fb8b17a51ae8270e973
+Subproject commit c13aa2f56f1ad3b1ab8475f1674f5851fa2f90da
diff --git a/sub-services/undergrad/src/main/java/cn/wustlinghang/wusthelper/internal/undergrad/exception/UndergradRpcException.java b/sub-services/undergrad/src/main/java/cn/wustlinghang/wusthelper/internal/undergrad/exception/UndergradRpcException.java
index c40c566..c652ff6 100644
--- a/sub-services/undergrad/src/main/java/cn/wustlinghang/wusthelper/internal/undergrad/exception/UndergradRpcException.java
+++ b/sub-services/undergrad/src/main/java/cn/wustlinghang/wusthelper/internal/undergrad/exception/UndergradRpcException.java
@@ -68,6 +68,8 @@ public class UndergradRpcException extends RpcException {
         AUTH_USER_DISABLED,
         // 用户账号需要更改
         AUTH_NEED_CHANGE_PASSWORD,
+        // 专属选课时间段账号被禁用（--> _ -->）
+        AUTH_BANNED_IN_EXCLUSIVE_TIME,
         AUTH_UNKNOWN_ERROR
     }
 }
diff --git a/sub-services/undergrad/src/main/java/cn/wustlinghang/wusthelper/internal/undergrad/services/LoginService.java b/sub-services/undergrad/src/main/java/cn/wustlinghang/wusthelper/internal/undergrad/services/LoginService.java
index c4fc1fa..a0177ba 100644
--- a/sub-services/undergrad/src/main/java/cn/wustlinghang/wusthelper/internal/undergrad/services/LoginService.java
+++ b/sub-services/undergrad/src/main/java/cn/wustlinghang/wusthelper/internal/undergrad/services/LoginService.java
@@ -41,7 +41,9 @@ public class LoginService {
 
     public boolean verify(String cookie) throws UndergradRpcException {
         try {
-            return !undergraduateLogin.checkCookiesFail(cookie);
+            return undergraduateLogin.testCookie(cookie);
+        } catch (ApiException e) {
+            return false;
         } catch (IOException e) {
             throw new UndergradRpcException(
                     UndergradRpcException.TypeCode.NETWORK_EXCEPTION,
@@ -59,6 +61,7 @@ public class LoginService {
             case UNI_LOGIN_USER_BANNED -> UndergradRpcException.ErrorCode.AUTH_USER_BANNED;
             case UNI_LOGIN_USER_DISABLED -> UndergradRpcException.ErrorCode.AUTH_USER_DISABLED;
             case UNI_LOGIN_NEED_CHANGE_PASSWORD -> UndergradRpcException.ErrorCode.AUTH_NEED_CHANGE_PASSWORD;
+            case UNDERGRAD_BANNED_IN_EXCLUSIVE_TIME -> UndergradRpcException.ErrorCode.AUTH_BANNED_IN_EXCLUSIVE_TIME;
             case UNI_LOGIN_USER_NOT_ONLY -> UndergradRpcException.ErrorCode.AUTH_UNKNOWN_ERROR;
             case UNI_LOGIN_NO_REGISTER -> UndergradRpcException.ErrorCode.AUTH_UNKNOWN_ERROR;
             case UNI_LOGIN_NEED_TFA -> UndergradRpcException.ErrorCode.AUTH_UNKNOWN_ERROR;