diff --git a/tests/i18n/tests.py b/tests/i18n/tests.py
index ddae4501ec..8248122a97 100644
--- a/tests/i18n/tests.py
+++ b/tests/i18n/tests.py
@@ -1254,6 +1254,7 @@ class FormattingTests(SimpleTestCase):
         self.assertEqual(get_format('DEBUG'), 'DEBUG')
 
     def test_get_custom_format(self):
+        reset_format_cache()
         with self.settings(FORMAT_MODULE_PATH='i18n.other.locale'):
             with translation.override('fr', deactivate=True):
                 self.assertEqual('d/m/Y CUSTOM', get_format('CUSTOM_DAY_FORMAT'))