diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index d3d08f2ff..ceab6111f 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -16,7 +16,7 @@ import datetime
 import inspect
 import types
 from decimal import Decimal
-from django.contrib.contenttypes.generic import GenericForeignKey
+from django.contrib.contenttypes.fields import GenericForeignKey
 from django.core.paginator import Page
 from django.db import models
 from django.forms import widgets
@@ -114,6 +114,9 @@ class OrderedDictWithMetadata(OrderedDict):
     """
     A sorted dict-like object, that can have additional properties attached.
     """
+    def __reduce__(self):
+        return self.__class__, (OrderedDict(self), )
+
     def __getstate__(self):
         """
         Used by pickle (e.g., caching).
diff --git a/rest_framework/settings.py b/rest_framework/settings.py
index 644751f87..c7830b665 100644
--- a/rest_framework/settings.py
+++ b/rest_framework/settings.py
@@ -19,9 +19,14 @@ back to the defaults.
 """
 from __future__ import unicode_literals
 from django.conf import settings
-from django.utils import importlib, six
+from django.utils import six
 from rest_framework import ISO_8601
 
+try:
+    import importlib
+except ImportError:
+    from django.utils import importlib
+
 
 USER_SETTINGS = getattr(settings, 'REST_FRAMEWORK', None)