diff --git a/django/conf/__init__.py b/django/conf/__init__.py
index e628af748c..199c34fb55 100644
--- a/django/conf/__init__.py
+++ b/django/conf/__init__.py
@@ -107,8 +107,10 @@ class BaseSettings(object):
         elif name == "ALLOWED_INCLUDE_ROOTS" and isinstance(value, six.string_types):
             raise ValueError("The ALLOWED_INCLUDE_ROOTS setting must be set "
                 "to a tuple, not a string.")
-        elif name == "INSTALLED_APPS" and len(value) != len(set(value)):
-            raise ImproperlyConfigured("The INSTALLED_APPS setting must contain unique values.")
+        elif name == "INSTALLED_APPS":
+            value = list(value)  # force evaluation of generators on Python 3
+            if len(value) != len(set(value)):
+                raise ImproperlyConfigured("The INSTALLED_APPS setting must contain unique values.")
 
         object.__setattr__(self, name, value)
 
diff --git a/tests/settings_tests/tests.py b/tests/settings_tests/tests.py
index 4031d09a58..a9503358a2 100644
--- a/tests/settings_tests/tests.py
+++ b/tests/settings_tests/tests.py
@@ -226,7 +226,7 @@ class TestComplexSettingOverride(TestCase):
             self.assertEqual('Overriding setting TEST_WARN can lead to unexpected behaviour.', str(w[-1].message))
 
 
-class UniqueSettngsTests(TestCase):
+class UniqueSettingsTests(TestCase):
     """
     Tests for the INSTALLED_APPS setting.
     """