diff --git a/polymorphic/tests.py b/polymorphic/tests.py
index 7005799..b485722 100644
--- a/polymorphic/tests.py
+++ b/polymorphic/tests.py
@@ -3,7 +3,7 @@
     Please see README.rst or DOCS.rst or http://bserve.webhop.org/wiki/django_polymorphic
 """
 
-import settings
+from django.conf import settings
 import sys
 from pprint import pprint
 
@@ -582,7 +582,7 @@ __test__ = {"doctest": """
 >>> type(ModelWithMyManager.objects)
 <class 'polymorphic.tests.MyManager'>
 >>> type(ModelWithMyManager._default_manager)
-<class 'polymorphic.tests.MyManager'>
+<class 'polymorphic.manager.PolymorphicManager'>
 
 
 ### Manager Inheritance
@@ -592,11 +592,11 @@ __test__ = {"doctest": """
 
 # check for correct default manager
 >>> type(MROBase1._default_manager)
-<class 'polymorphic.tests.MyManager'>
+<class 'polymorphic.manager.PolymorphicManager'>
 
 # Django vanilla inheritance does not inherit MyManager as _default_manager here
 >>> type(MROBase2._default_manager)
-<class 'polymorphic.tests.MyManager'>
+<class 'polymorphic.manager.PolymorphicManager'>
 
 
 ### fixed issue in PolymorphicModel.__getattribute__: field name same as model name
diff --git a/polymorphic/tools_for_tests.py b/polymorphic/tools_for_tests.py
index 1646a4a..9c75bb8 100644
--- a/polymorphic/tools_for_tests.py
+++ b/polymorphic/tools_for_tests.py
@@ -84,7 +84,9 @@ class UUIDField(models.CharField):
 
     def db_type(self, connection):
         from django.conf import settings
-        return UUIDField._CREATE_COLUMN_TYPES.get(settings.DATABASE_ENGINE, "char(%s)" % self.max_length)
+        full_database_type = settings.DATABASES['default']['ENGINE']
+        database_type = full_database_type.split('.')[-1]
+        return UUIDField._CREATE_COLUMN_TYPES.get(database_type, "char(%s)" % self.max_length)
 
     def to_python(self, value):
         """Return a uuid.UUID instance from the value returned by the database."""
diff --git a/settings.py b/settings.py
index 4439e8f..f95cfe7 100644
--- a/settings.py
+++ b/settings.py
@@ -9,28 +9,12 @@ ADMINS = (
 
 MANAGERS = ADMINS
 
-import django
-import os
-
-if os.path.ismount('/ram'):
-    SQLITE_DB_PATH = '/ram/django-polymorphic-test-db.sqlite3'
-else:
-    SQLITE_DB_PATH = '/var/tmp/django-polymorphic-test-db.sqlite3'
-
-if django.VERSION[:2][0]>=1 and django.VERSION[:2][1]>=3:
-    DATABASES = {
-        'default': {
-            'ENGINE': 'django.db.backends.sqlite3',
-            'NAME': SQLITE_DB_PATH
-        }
+DATABASES = {
+    'default': {
+        'ENGINE': 'django.db.backends.sqlite3',
+        'NAME': ':memory:'
     }
-else:
-    DATABASE_ENGINE = 'sqlite3'           # 'postgresql_psycopg2', 'postgresql', 'mysql', 'sqlite3' or 'oracle'.
-    DATABASE_NAME = SQLITE_DB_PATH             # Or path to database file if using sqlite3.
-    DATABASE_USER = ''             # Not used with sqlite3.
-    DATABASE_PASSWORD = ''         # Not used with sqlite3.
-    DATABASE_HOST = ''             # Set to empty string for localhost. Not used with sqlite3.
-    DATABASE_PORT = ''             # Set to empty string for default. Not used with sqlite3.
+}
 
 # Local time zone for this installation. Choices can be found here:
 # http://en.wikipedia.org/wiki/List_of_tz_zones_by_name
diff --git a/tox.ini b/tox.ini
new file mode 100644
index 0000000..681be81
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,33 @@
+[tox]
+envlist=
+    py26-django15,
+    py27-django15,
+    py26-django14,
+    py27-django14,
+
+[testenv]
+commands=
+    python manage.py test
+
+# Build configurations
+
+[testenv:py26-django15]
+basepython=python2.6
+deps=
+    django==1.5
+
+[testenv:py27-django15]
+basepython=python2.7
+deps=
+    django==1.5
+
+[testenv:py26-django14]
+basepython=python2.6
+deps=
+    django==1.4.5
+
+[testenv:py27-django14]
+basepython=python2.7
+deps=
+    django==1.4.5
+