diff --git a/wagtail/contrib/wagtailsearchpromotions/tests.py b/wagtail/contrib/wagtailsearchpromotions/tests.py
index 15830d4d9..66a047ceb 100644
--- a/wagtail/contrib/wagtailsearchpromotions/tests.py
+++ b/wagtail/contrib/wagtailsearchpromotions/tests.py
@@ -1,3 +1,5 @@
+import unittest
+
 from django.test import TestCase
 from django.core.urlresolvers import reverse
 
@@ -71,6 +73,11 @@ class TestGetSearchPromotionsTemplateTag(TestCase):
         search_picks = list(get_search_promotions("root page"))
         self.assertEqual(search_picks, [pick])
 
+    @unittest.expectedFailure
+    def test_get_search_promotions_with_none_query_string(self):
+        search_picks = list(get_search_promotions(None))
+        self.assertEqual(search_picks, [])
+
 
 class TestSearchPromotionsIndexView(TestCase, WagtailTestUtils):
     def setUp(self):