diff --git a/django/core/management/__init__.py b/django/core/management/__init__.py
index adc7d173eb..cf6b60c93e 100644
--- a/django/core/management/__init__.py
+++ b/django/core/management/__init__.py
@@ -229,7 +229,7 @@ class ManagementUtility:
                 # (get_commands() swallows the original one) so the user is
                 # informed about it.
                 settings.INSTALLED_APPS
-            else:
+            elif not settings.configured:
                 sys.stderr.write("No Django settings specified.\n")
             possible_matches = get_close_matches(subcommand, commands)
             sys.stderr.write('Unknown command: %r' % subcommand)
diff --git a/tests/admin_scripts/tests.py b/tests/admin_scripts/tests.py
index 1e4477ed34..de220f0282 100644
--- a/tests/admin_scripts/tests.py
+++ b/tests/admin_scripts/tests.py
@@ -634,6 +634,15 @@ class DjangoAdminSettingsDirectory(AdminScriptTestCase):
 # of the generated manage.py script
 ##########################################################################
 
+class ManageManullyConfiguredSettings(AdminScriptTestCase):
+    """Customized manage.py calling settings.configure()."""
+    def test_non_existent_command_output(self):
+        out, err = self.run_manage(['invalid_command'], manage_py='configured_settings_manage.py')
+        self.assertNoOutput(out)
+        self.assertOutput(err, "Unknown command: 'invalid_command'")
+        self.assertNotInOutput(err, 'No Django settings specified')
+
+
 class ManageNoSettings(AdminScriptTestCase):
     "A series of tests for manage.py when there is no settings.py file."