diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index 163abf4f0..325b73b4a 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -323,6 +323,8 @@ class BaseSerializer(WritableField):
             field.initialize(parent=self, field_name=field_name)
             key = self.get_field_key(field_name)
             value = field.field_to_native(obj, field_name)
+            if value == None and hasattr(field, 'default'):
+                value = field.default
             method = getattr(self, 'transform_%s' % field_name, None)
             if callable(method):
                 value = method(obj, value)
diff --git a/rest_framework/tests/test_serializer.py b/rest_framework/tests/test_serializer.py
index 1d621aa2f..6cd3093f3 100644
--- a/rest_framework/tests/test_serializer.py
+++ b/rest_framework/tests/test_serializer.py
@@ -1722,7 +1722,7 @@ class TestSerializerTransformMethods(TestCase):
         )
 class DefaultTrueBooleanModel(models.Model):
     cat = models.BooleanField(default=True)
-    dog = models.BooleanField(default=True)
+    dog = models.BooleanField(default=False)
 
 class SerializerDefaultTrueBoolean(TestCase):
 
@@ -1738,18 +1738,20 @@ class SerializerDefaultTrueBoolean(TestCase):
 
     def test_blank_input(self):
         serializer = self.default_true_boolean_serializer()
-        self.assertEqual(serializer.data['dog'], True)
         self.assertEqual(serializer.data['cat'], True)
-
-
+        self.assertEqual(serializer.data['dog'], False)
 
     def test_enabled_as_false(self):
         serializer = self.default_true_boolean_serializer({'cat': False, 'dog': False})
         self.assertEqual(serializer.data['cat'], False)
         self.assertEqual(serializer.data['dog'], False)
 
-
     def test_enabled_as_true(self):
         serializer = self.default_true_boolean_serializer({'cat': True, 'dog': True})
         self.assertEqual(serializer.data['cat'], True)
         self.assertEqual(serializer.data['dog'], True)
+
+    def test_enabled_partial(self):
+	serializer = self.default_true_boolean_serializer({'cat': False})
+        self.assertEqual(serializer.data['cat'], False)
+        self.assertEqual(serializer.data['dog'], False)