diff --git a/tests/settings/main.py b/tests/settings/main.py
index f066f31..f9d71d1 100644
--- a/tests/settings/main.py
+++ b/tests/settings/main.py
@@ -38,9 +38,9 @@ class Test(Configuration):
         TEST_RUNNER = 'discover_runner.DiscoverRunner'
 
     def TEMPLATE_CONTEXT_PROCESSORS(self):
-        return Configuration.TEMPLATE_CONTEXT_PROCESSORS + [
+        return tuple(Configuration.TEMPLATE_CONTEXT_PROCESSORS) + (
             'tests.settings.base.test_callback',
-        ]
+        )
 
     ATTRIBUTE_SETTING = True
 
diff --git a/tests/settings/mixin_inheritance.py b/tests/settings/mixin_inheritance.py
index 24c3a47..e8d6b5f 100644
--- a/tests/settings/mixin_inheritance.py
+++ b/tests/settings/mixin_inheritance.py
@@ -5,7 +5,7 @@ class Mixin1(object):
 
     @property
     def TEMPLATE_CONTEXT_PROCESSORS(self):
-        return super(Mixin1, self).TEMPLATE_CONTEXT_PROCESSORS + (
+        return tuple(super(Mixin1, self).TEMPLATE_CONTEXT_PROCESSORS) + (
             'some_app.context_processors.processor1',)
 
 
@@ -13,7 +13,7 @@ class Mixin2(object):
 
     @property
     def TEMPLATE_CONTEXT_PROCESSORS(self):
-        return super(Mixin2, self).TEMPLATE_CONTEXT_PROCESSORS + (
+        return tuple(super(Mixin2, self).TEMPLATE_CONTEXT_PROCESSORS) + (
             'some_app.context_processors.processor2',)
 
 
@@ -21,5 +21,5 @@ class Inheritance(Mixin2, Mixin1, Configuration):
 
     @property
     def TEMPLATE_CONTEXT_PROCESSORS(self):
-        return super(Inheritance, self).TEMPLATE_CONTEXT_PROCESSORS + (
+        return tuple(super(Inheritance, self).TEMPLATE_CONTEXT_PROCESSORS) + (
             'some_app.context_processors.processorbase',)
diff --git a/tests/settings/multiple_inheritance.py b/tests/settings/multiple_inheritance.py
index 39f07f2..76b3be8 100644
--- a/tests/settings/multiple_inheritance.py
+++ b/tests/settings/multiple_inheritance.py
@@ -4,5 +4,5 @@ from .main import Test
 class Inheritance(Test):
 
     def TEMPLATE_CONTEXT_PROCESSORS(self):
-        return super(Inheritance, self).TEMPLATE_CONTEXT_PROCESSORS() + (
+        return tuple(super(Inheritance, self).TEMPLATE_CONTEXT_PROCESSORS()) + (
             'tests.settings.base.test_callback',)
diff --git a/tests/settings/single_inheritance.py b/tests/settings/single_inheritance.py
index 70f9a81..5377ef0 100644
--- a/tests/settings/single_inheritance.py
+++ b/tests/settings/single_inheritance.py
@@ -4,5 +4,5 @@ from .base import Base
 class Inheritance(Base):
 
     def TEMPLATE_CONTEXT_PROCESSORS(self):
-        return super(Inheritance, self).TEMPLATE_CONTEXT_PROCESSORS + (
+        return tuple(super(Inheritance, self).TEMPLATE_CONTEXT_PROCESSORS) + (
             'tests.settings.base.test_callback',)
diff --git a/tests/test_inheritance.py b/tests/test_inheritance.py
index f5e76a9..e29c570 100644
--- a/tests/test_inheritance.py
+++ b/tests/test_inheritance.py
@@ -14,9 +14,9 @@ class InheritanceTests(TestCase):
     def test_inherited(self):
         from tests.settings import single_inheritance
         self.assertEqual(single_inheritance.TEMPLATE_CONTEXT_PROCESSORS,
-                         global_settings.TEMPLATE_CONTEXT_PROCESSORS + (
-                             'tests.settings.base.test_callback',
-                         ))
+                         tuple(global_settings.TEMPLATE_CONTEXT_PROCESSORS) + (
+                                  'tests.settings.base.test_callback',
+                               ))
 
     @patch.dict(os.environ, clear=True,
                 DJANGO_CONFIGURATION='Inheritance',
@@ -24,10 +24,10 @@ class InheritanceTests(TestCase):
     def test_inherited2(self):
         from tests.settings import multiple_inheritance
         self.assertEqual(multiple_inheritance.TEMPLATE_CONTEXT_PROCESSORS,
-                         global_settings.TEMPLATE_CONTEXT_PROCESSORS + (
-                             'tests.settings.base.test_callback',
-                             'tests.settings.base.test_callback',
-                         ))
+                         tuple(global_settings.TEMPLATE_CONTEXT_PROCESSORS) + (
+                                  'tests.settings.base.test_callback',
+                                  'tests.settings.base.test_callback',
+                              ))
 
     @patch.dict(os.environ, clear=True,
                 DJANGO_CONFIGURATION='Inheritance',
@@ -35,8 +35,8 @@ class InheritanceTests(TestCase):
     def test_inherited3(self):
         from tests.settings import mixin_inheritance
         self.assertEqual(mixin_inheritance.TEMPLATE_CONTEXT_PROCESSORS,
-                         global_settings.TEMPLATE_CONTEXT_PROCESSORS + (
-                             'some_app.context_processors.processor1',
-                             'some_app.context_processors.processor2',
-                             'some_app.context_processors.processorbase',
-                         ))
+                         tuple(global_settings.TEMPLATE_CONTEXT_PROCESSORS) + (
+                                   'some_app.context_processors.processor1',
+                                   'some_app.context_processors.processor2',
+                                   'some_app.context_processors.processorbase',
+                               ))
diff --git a/tests/test_main.py b/tests/test_main.py
index 84eea83..3956129 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -23,9 +23,9 @@ class MainTests(TestCase):
         self.assertNotEqual(main.PRISTINE_FUNCTION_SETTING, 5)
         self.assertTrue(lambda: callable(main.PRISTINE_FUNCTION_SETTING))
         self.assertEqual(main.TEMPLATE_CONTEXT_PROCESSORS,
-                         global_settings.TEMPLATE_CONTEXT_PROCESSORS + (
-                             'tests.settings.base.test_callback',
-                         ))
+                         tuple(global_settings.TEMPLATE_CONTEXT_PROCESSORS) + (
+                                   'tests.settings.base.test_callback',
+                               ))
         self.assertEqual(main.PRE_SETUP_TEST_SETTING, 6)
         self.assertRaises(AttributeError, lambda: main.POST_SETUP_TEST_SETTING)
         self.assertEqual(main.Test.POST_SETUP_TEST_SETTING, 7)