diff --git a/casbin_sqlalchemy_adapter/adapter.py b/casbin_sqlalchemy_adapter/adapter.py
index 6dc3200..d4fc239 100644
--- a/casbin_sqlalchemy_adapter/adapter.py
+++ b/casbin_sqlalchemy_adapter/adapter.py
@@ -3,10 +3,11 @@
 from casbin import persist
 from sqlalchemy import Column, Integer, String
 from sqlalchemy import create_engine, or_
-from sqlalchemy.ext.declarative import declarative_base
-from sqlalchemy.orm import sessionmaker
+from sqlalchemy.orm import sessionmaker, DeclarativeBase
 
-Base = declarative_base()
+# declarative base class
+class Base(DeclarativeBase):
+    pass
 
 
 class CasbinRule(Base):