diff --git a/src/suou/__init__.py b/src/suou/__init__.py
index 9108eac..ceeb709 100644
--- a/src/suou/__init__.py
+++ b/src/suou/__init__.py
@@ -33,7 +33,7 @@ from .strtools import PrefixIdentifier
 from .validators import matches
 from .redact import redact_url_password
 
-__version__ = "0.5.0-dev30"
+__version__ = "0.5.0-dev31"
 
 __all__ = (
     'ConfigOptions', 'ConfigParserConfigSource', 'ConfigSource', 'ConfigValue',
diff --git a/src/suou/sqlalchemy_async.py b/src/suou/sqlalchemy_async.py
index cd082b8..42045fc 100644
--- a/src/suou/sqlalchemy_async.py
+++ b/src/suou/sqlalchemy_async.py
@@ -41,8 +41,9 @@ class SQLAlchemy:
     async def begin(self) -> AsyncSession:
         if self.engine is None:
             raise RuntimeError('database is not connected')
-        return await self.engine.begin()
-    __aenter__ = begin
+        return self.engine.begin()
+    async def __aenter__(self):
+        return self.begin()
     async def __aexit__(self, e1, e2, e3):
         return await self.engine.__aexit__(e1, e2, e3)
     async def paginate(self, select: Select, *,