diff --git a/tests/regressiontests/forms/fields.py b/tests/regressiontests/forms/fields.py
index 990a9f7..053071c 100644
--- a/tests/regressiontests/forms/fields.py
+++ b/tests/regressiontests/forms/fields.py
@@ -718,6 +718,7 @@ class FieldsTests(TestCase):
         self.assertRaisesErrorWithMessage(ValidationError, "[u'Enter a list of values.']", f.clean, 'hello')
         self.assertRaisesErrorWithMessage(ValidationError, "[u'This field is required.']", f.clean, [])
         self.assertRaisesErrorWithMessage(ValidationError, "[u'This field is required.']", f.clean, ())
+        self.assertRaisesErrorWithMessage(ValidationError, "[u'This field is required.']", f.clean, frozenset([]))
         self.assertRaisesErrorWithMessage(ValidationError, "[u'Select a valid choice. 3 is not one of the available choices.']", f.clean, ['3'])
 
     def test_multiplechoicefield_61(self):