diff --git a/casbin_sqlalchemy_adapter/adapter.py b/casbin_sqlalchemy_adapter/adapter.py
index d85681c..1666be9 100644
--- a/casbin_sqlalchemy_adapter/adapter.py
+++ b/casbin_sqlalchemy_adapter/adapter.py
@@ -46,7 +46,7 @@ class Filter:
 class Adapter(persist.Adapter, persist.adapters.UpdateAdapter):
     """the interface for Casbin adapters."""
 
-    def __init__(self, engine, db_class=None, filtered=False):
+    def __init__(self, engine, db_class= None, filtered=False):
         if isinstance(engine, str):
             self._engine = create_engine(engine)
         else:
@@ -54,6 +54,12 @@ def __init__(self, engine, db_class=None, filtered=False):
 
         if db_class is None:
             db_class = CasbinRule
+        else:
+            for attr in ('ptype', 'v0', 'v1', 'v2', 'v3', 'v4', 'v5'):
+                if not hasattr(db_class, attr):
+                    raise Exception(f'{attr} not found in custom DatabaseClass.')
+            Base.metadata = db_class.metadata
+
         self._db_class = db_class
         self.session_local = sessionmaker(bind=self._engine)
 
@@ -185,7 +191,7 @@ def remove_filtered_policy(self, sec, ptype, field_index, *field_values):
         return True if r > 0 else False
 
     def update_policy(
-        self, sec: str, ptype: str, old_rule: [str], new_rule: [str]
+            self, sec: str, ptype: str, old_rule: [str], new_rule: [str]
     ) -> None:
         """
         Update the old_rule with the new_rule in the database (storage).
@@ -218,15 +224,15 @@ def update_policy(
                     exec(f"old_rule_line.v{index} = None")
 
     def update_policies(
-        self,
-        sec: str,
-        ptype: str,
-        old_rules: [
-            [str],
-        ],
-        new_rules: [
-            [str],
-        ],
+            self,
+            sec: str,
+            ptype: str,
+            old_rules: [
+                [str],
+            ],
+            new_rules: [
+                [str],
+            ],
     ) -> None:
         """
         Update the old_rules with the new_rules in the database (storage).
diff --git a/tests/test_adapter.py b/tests/test_adapter.py
index 7c34280..f3819f8 100644
--- a/tests/test_adapter.py
+++ b/tests/test_adapter.py
@@ -1,12 +1,14 @@
+import os
+from unittest import TestCase
+
+import casbin
+from sqlalchemy import create_engine, Column, Integer, String
+from sqlalchemy.orm import sessionmaker
+
 from casbin_sqlalchemy_adapter import Adapter
 from casbin_sqlalchemy_adapter import Base
 from casbin_sqlalchemy_adapter import CasbinRule
 from casbin_sqlalchemy_adapter.adapter import Filter
-from sqlalchemy import create_engine
-from sqlalchemy.orm import sessionmaker
-from unittest import TestCase
-import casbin
-import os
 
 
 def get_fixture(path):
@@ -35,6 +37,30 @@ def get_enforcer():
 
 
 class TestConfig(TestCase):
+    def test_custom_db_class(self):
+        class CustomRule(Base):
+            __tablename__ = "casbin_rule2"
+
+            id = Column(Integer, primary_key=True)
+            ptype = Column(String(255))
+            v0 = Column(String(255))
+            v1 = Column(String(255))
+            v2 = Column(String(255))
+            v3 = Column(String(255))
+            v4 = Column(String(255))
+            v5 = Column(String(255))
+            not_exist = Column(String(255))
+
+        engine = create_engine("sqlite://")
+        adapter = Adapter(engine, CustomRule)
+
+        session = sessionmaker(bind=engine)
+        Base.metadata.create_all(engine)
+        s = session()
+        s.add(CustomRule(not_exist="NotNone"))
+        s.commit()
+        self.assertEqual(s.query(CustomRule).all()[0].not_exist, "NotNone")
+
     def test_enforcer_basic(self):
         e = get_enforcer()