diff --git a/ming/tests/test_declarative.py b/ming/tests/test_declarative.py
index 7557cf0..7be426d 100644
--- a/ming/tests/test_declarative.py
+++ b/ming/tests/test_declarative.py
@@ -1,3 +1,4 @@
+import os
 from unittest import TestCase
 from collections import defaultdict
 
@@ -6,9 +7,11 @@
 from pymongo.errors import AutoReconnect
 
 from ming.base import Cursor
+from ming.datastore import create_datastore
 from ming.declarative import Document
 from ming.metadata import Field, Index
 from ming import schema as S
+from ming.odm.odmsession import ODMSession, ThreadLocalODMSession
 from ming.session import Session
 from ming.exc import MingException
 
@@ -128,6 +131,45 @@ def test_migrate(self):
         self.MockSession.find.assert_called_with(self.TestDoc)
         self.MockSession.save.assert_called_with(doc)
 
+class TestDocumentReal(TestCase):
+    DATASTORE = f"mongodb://localhost/test_ming_TestDocumentReal_{os.getpid()}?serverSelectionTimeoutMS=100"
+
+    def setUp(self):
+        self.datastore = create_datastore(self.DATASTORE)
+        self.session = Session(bind=self.datastore)
+
+        class TestDoc(Document):
+            class __mongometa__:
+                name='test_doc'
+                session = self.session
+                indexes = [ ('a',) ]
+            _id = Field(S.Anything)
+            a=Field(S.Int, if_missing=None)
+            b=Field(S.Object(dict(a=S.Int(if_missing=None))))
+        class TestDocNoSchema(Document):
+            class __mongometa__:
+                name='test_doc'
+                session = self.session
+        self.TestDoc = TestDoc
+        self.TestDocNoSchema = TestDocNoSchema
+    def tearDown(self):
+        self.TestDoc.m.remove()
+        self.TestDocNoSchema.m.remove()
+
+    def test_field(self):
+        doc = self.TestDoc(dict(_id=1, a=1, b=dict(a=5)))
+        doc.m.save()
+
+        self.assertEqual(doc.a, 1)
+        self.assertEqual(doc.b, dict(a=5))
+        doc.a = 5
+        self.assertEqual(doc, dict(_id=1, a=5, b=dict(a=5)))
+        del doc.a
+        self.assertEqual(doc, dict(_id=1, b=dict(a=5)))
+        self.assertRaises(AttributeError, getattr, doc, 'c')
+        self.assertRaises(AttributeError, getattr, doc, 'a')
+        self.assertEqual(self.session.count(self.TestDoc), 1)
+
 class TestIndexes(TestCase):
 
     def setUp(self):