diff --git a/server/books/tests/test_module_mutations.py b/server/books/tests/test_module_mutations.py
index 8058c804..6b069a69 100644
--- a/server/books/tests/test_module_mutations.py
+++ b/server/books/tests/test_module_mutations.py
@@ -4,13 +4,15 @@ from graphql_relay import to_global_id
 
 from api.schema import schema
 from api.utils import get_graphql_mutation, get_object
-from books.factories import ContentBlockFactory
+from books.factories import ContentBlockFactory, ModuleFactory
 from books.models import ContentBlock
 
 
 class NewContentBlockMutationTest(TestCase):
     def setUp(self):
-        content_block = ContentBlockFactory()
+        module = ModuleFactory()
+        content_block = ContentBlockFactory(module=module)
+
         self.sibling_id = to_global_id('ContentBlock', content_block.pk)
 
     def test_add_new_content_block(self):