diff --git a/docs/changelog.rst b/docs/changelog.rst
index 2820ed5f..638c0e80 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -2,6 +2,10 @@
 Changelog
 =========
 
+Changes in 0.7.5
+================
+- ReferenceFields with dbref=False use ObjectId instead of strings (MongoEngine/mongoengine#134)
+  See ticket for upgrade notes (https://github.com/MongoEngine/mongoengine/issues/134)
 
 Changes in 0.7.4
 ================
diff --git a/mongoengine/__init__.py b/mongoengine/__init__.py
index 22f0334e..9044e617 100644
--- a/mongoengine/__init__.py
+++ b/mongoengine/__init__.py
@@ -12,7 +12,7 @@ from signals import *
 __all__ = (document.__all__ + fields.__all__ + connection.__all__ +
            queryset.__all__ + signals.__all__)
 
-VERSION = (0, 7, 4)
+VERSION = (0, 7, 5)
 
 
 def get_version():
diff --git a/mongoengine/fields.py b/mongoengine/fields.py
index e8d92360..12cc7f2a 100644
--- a/mongoengine/fields.py
+++ b/mongoengine/fields.py
@@ -792,7 +792,7 @@ class ReferenceField(BaseField):
             collection = self.document_type._get_collection_name()
             return DBRef(collection, id_)
 
-        return "%s" % id_
+        return id_
 
     def to_python(self, value):
         """Convert a MongoDB-compatible type to a Python type.
diff --git a/python-mongoengine.spec b/python-mongoengine.spec
index 8a3d4751..641b3def 100644
--- a/python-mongoengine.spec
+++ b/python-mongoengine.spec
@@ -5,7 +5,7 @@
 %define srcname mongoengine
 
 Name:           python-%{srcname}
-Version:        0.7.4
+Version:        0.7.5
 Release:        1%{?dist}
 Summary:        A Python Document-Object Mapper for working with MongoDB
 
diff --git a/tests/test_dereference.py b/tests/test_dereference.py
index 120b1a26..0d757fd7 100644
--- a/tests/test_dereference.py
+++ b/tests/test_dereference.py
@@ -1,7 +1,7 @@
 from __future__ import with_statement
 import unittest
 
-from bson import DBRef
+from bson import DBRef, ObjectId
 
 from mongoengine import *
 from mongoengine.connection import get_db
@@ -187,8 +187,8 @@ class FieldTest(unittest.TestCase):
         self.assertEqual(group.members, [user])
 
         raw_data = Group._get_collection().find_one()
-        self.assertTrue(isinstance(raw_data['author'], basestring))
-        self.assertTrue(isinstance(raw_data['members'][0], basestring))
+        self.assertTrue(isinstance(raw_data['author'], ObjectId))
+        self.assertTrue(isinstance(raw_data['members'][0], ObjectId))
 
     def test_recursive_reference(self):
         """Ensure that ReferenceFields can reference their own documents.
diff --git a/tests/test_fields.py b/tests/test_fields.py
index ce80bf9c..04c3765c 100644
--- a/tests/test_fields.py
+++ b/tests/test_fields.py
@@ -7,7 +7,7 @@ import tempfile
 
 from decimal import Decimal
 
-from bson import Binary, DBRef
+from bson import Binary, DBRef, ObjectId
 import gridfs
 
 from nose.plugins.skip import SkipTest
@@ -1104,7 +1104,7 @@ class FieldTest(unittest.TestCase):
         p = Person.objects.get(name="Ross")
         self.assertEqual(p.parent, p1)
 
-    def test_str_reference_fields(self):
+    def test_objectid_reference_fields(self):
 
         class Person(Document):
             name = StringField()
@@ -1117,7 +1117,7 @@ class FieldTest(unittest.TestCase):
 
         col = Person._get_collection()
         data = col.find_one({'name': 'Ross'})
-        self.assertEqual(data['parent'], "%s" % p1.pk)
+        self.assertEqual(data['parent'], p1.pk)
 
         p = Person.objects.get(name="Ross")
         self.assertEqual(p.parent, p1)