diff --git a/backend/app/db/models.py b/backend/app/db/models.py
index 39a3323..8149578 100644
--- a/backend/app/db/models.py
+++ b/backend/app/db/models.py
@@ -8,7 +8,7 @@ from app.core.security import chacha20Decrypt
 class Base:
     id = Column(Integer, primary_key=True, index=True)
     create_time = Column(DateTime, default=datetime.now(timezone.utc))
-    update_time = Column(DateTime, default=datetime.now(timezone.utc), onupdate=datetime.now(timezone.utc))
+    update_time = Column(DateTime, default=datetime.now(timezone.utc), onupdate=lambda: datetime.now(timezone.utc))
 
 
 userrole = Table(