diff --git a/polymorphic/managers.py b/polymorphic/managers.py
index 41fdbd9..875d40b 100644
--- a/polymorphic/managers.py
+++ b/polymorphic/managers.py
@@ -8,7 +8,13 @@ import django
 from django.db import models
 from polymorphic.query import PolymorphicQuerySet
 
+try:
+    from django.utils.six import python_2_unicode_compatible
+except ImportError:
+    from django.utils.encoding import python_2_unicode_compatible  # Django 1.5
 
+
+@python_2_unicode_compatible
 class PolymorphicManager(models.Manager):
     """
     Manager for PolymorphicModel
@@ -44,7 +50,7 @@ class PolymorphicManager(models.Manager):
     if django.VERSION < (1, 7):
         get_query_set = get_queryset
 
-    def __unicode__(self):
+    def __str__(self):
         return '%s (PolymorphicManager) using %s' % (self.__class__.__name__, self.queryset_class.__name__)
 
     # Proxied methods
diff --git a/polymorphic/showfields.py b/polymorphic/showfields.py
index a7270d5..360b847 100644
--- a/polymorphic/showfields.py
+++ b/polymorphic/showfields.py
@@ -28,7 +28,7 @@ class ShowFieldBase(object):
     polymorphic_showfield_old_format = False
 
     def __repr__(self):
-        return self.__unicode__()
+        return self.__str__()
 
     def _showfields_get_content(self, field_name, field_type=type(None)):
         "helper for __unicode__"