diff --git a/model_utils/managers.py b/model_utils/managers.py
index 74cc7bc..1f502ad 100644
--- a/model_utils/managers.py
+++ b/model_utils/managers.py
@@ -38,7 +38,7 @@ class InheritanceQuerySet(QuerySet):
 
     def annotate(self, *args, **kwargs):
         qset = super(InheritanceQuerySet, self).annotate(*args, **kwargs)
-        qset._annotated = [a.default_alias for a in args] + kwargs.keys()
+        qset._annotated = [a.default_alias for a in args] + list(kwargs.keys())
         return qset
 
 
diff --git a/model_utils/tests/tests.py b/model_utils/tests/tests.py
index 1b94abd..02b69ce 100644
--- a/model_utils/tests/tests.py
+++ b/model_utils/tests/tests.py
@@ -654,7 +654,7 @@ class ModelTrackerTestCase(TestCase):
 
     def assertHasChanged(self, **kwargs):
         tracker = kwargs.pop('tracker', self.tracker)
-        for field, value in kwargs.iteritems():
+        for field, value in kwargs.items():
             if value is None:
                 self.assertRaises(FieldError, tracker.has_changed, field)
             else:
@@ -662,7 +662,7 @@ class ModelTrackerTestCase(TestCase):
 
     def assertPrevious(self, **kwargs):
         tracker = kwargs.pop('tracker', self.tracker)
-        for field, value in kwargs.iteritems():
+        for field, value in kwargs.items():
             self.assertEqual(tracker.previous(field), value)
 
     def assertChanged(self, **kwargs):
@@ -674,7 +674,7 @@ class ModelTrackerTestCase(TestCase):
         self.assertEqual(tracker.current(), kwargs)
 
     def update_instance(self, **kwargs):
-        for field, value in kwargs.iteritems():
+        for field, value in kwargs.items():
             setattr(self.instance, field, value)
         self.instance.save()
 
diff --git a/model_utils/tracker.py b/model_utils/tracker.py
index d93dfea..9a83f1d 100644
--- a/model_utils/tracker.py
+++ b/model_utils/tracker.py
@@ -74,6 +74,6 @@ class ModelInstanceTracker(object):
         """Returns dict of fields that changed since save (with old values)"""
         if not self.instance.pk:
             return {}
-        saved = self.saved_data.iteritems()
+        saved = self.saved_data.items()
         current = self.current()
         return dict((k, v) for k, v in saved if v != current[k])