diff --git a/rest_framework/settings.py b/rest_framework/settings.py
index 79da23ca4..33f848138 100644
--- a/rest_framework/settings.py
+++ b/rest_framework/settings.py
@@ -48,7 +48,6 @@ DEFAULTS = {
     'DEFAULT_METADATA_CLASS': 'rest_framework.metadata.SimpleMetadata',
 
     # Generic view behavior
-    'DEFAULT_MODEL_SERIALIZER_CLASS': 'rest_framework.serializers.ModelSerializer',
     'DEFAULT_PAGINATION_SERIALIZER_CLASS': 'rest_framework.pagination.PaginationSerializer',
     'DEFAULT_FILTER_BACKENDS': (),
 
@@ -124,7 +123,6 @@ IMPORT_STRINGS = (
     'DEFAULT_THROTTLE_CLASSES',
     'DEFAULT_CONTENT_NEGOTIATION_CLASS',
     'DEFAULT_METADATA_CLASS',
-    'DEFAULT_MODEL_SERIALIZER_CLASS',
     'DEFAULT_PAGINATION_SERIALIZER_CLASS',
     'DEFAULT_FILTER_BACKENDS',
     'EXCEPTION_HANDLER',
@@ -176,8 +174,8 @@ class APISettings(object):
     """
     def __init__(self, user_settings=None, defaults=None, import_strings=None):
         self.user_settings = user_settings or {}
-        self.defaults = defaults or {}
-        self.import_strings = import_strings or ()
+        self.defaults = defaults or DEFAULTS
+        self.import_strings = import_strings or IMPORT_STRINGS
 
     def __getattr__(self, attr):
         if attr not in self.defaults.keys():
diff --git a/tests/extras/__init__.py b/tests/extras/__init__.py
deleted file mode 100644
index e69de29bb..000000000
diff --git a/tests/extras/bad_import.py b/tests/extras/bad_import.py
deleted file mode 100644
index 68263d947..000000000
--- a/tests/extras/bad_import.py
+++ /dev/null
@@ -1 +0,0 @@
-raise ValueError
diff --git a/tests/test_settings.py b/tests/test_settings.py
index e29fc34aa..f2ff4ca14 100644
--- a/tests/test_settings.py
+++ b/tests/test_settings.py
@@ -1,22 +1,17 @@
-"""Tests for the settings module"""
 from __future__ import unicode_literals
 from django.test import TestCase
-
-from rest_framework.settings import APISettings, DEFAULTS, IMPORT_STRINGS
+from rest_framework.settings import APISettings
 
 
 class TestSettings(TestCase):
-    """Tests relating to the api settings"""
-
-    def test_non_import_errors(self):
-        """Make sure other errors aren't suppressed."""
-        settings = APISettings({'DEFAULT_MODEL_SERIALIZER_CLASS': 'tests.extras.bad_import.ModelSerializer'}, DEFAULTS, IMPORT_STRINGS)
-        with self.assertRaises(ValueError):
-            settings.DEFAULT_MODEL_SERIALIZER_CLASS
-
     def test_import_error_message_maintained(self):
-        """Make sure real import errors are captured and raised sensibly."""
-        settings = APISettings({'DEFAULT_MODEL_SERIALIZER_CLASS': 'tests.extras.not_here.ModelSerializer'}, DEFAULTS, IMPORT_STRINGS)
-        with self.assertRaises(ImportError) as cm:
-            settings.DEFAULT_MODEL_SERIALIZER_CLASS
-        self.assertTrue('ImportError' in str(cm.exception))
+        """
+        Make sure import errors are captured and raised sensibly.
+        """
+        settings = APISettings({
+            'DEFAULT_RENDERER_CLASSES': [
+                'tests.invalid_module.InvalidClassName'
+            ]
+        })
+        with self.assertRaises(ImportError):
+            settings.DEFAULT_RENDERER_CLASSES