diff --git a/server/books/tests/test_duplicate_contents.py b/server/books/tests/test_duplicate_contents.py
index 86e5f4ac..d5beebf4 100644
--- a/server/books/tests/test_duplicate_contents.py
+++ b/server/books/tests/test_duplicate_contents.py
@@ -1,9 +1,12 @@
 from django.test import TestCase
+from wagtail.rich_text import RichText
 from assignments.models import Assignment
+from assignments.factories import AssignmentFactory
 
 from books.factories import BookFactory, ContentBlockFactory
 from books.models.contentblock import ContentBlock
 from core.logger import get_logger
+from surveys.factories import SurveyFactory
 from surveys.models import Survey
 from users.services import create_users
 
@@ -14,20 +17,18 @@ class DuplicateContentsTestCase(TestCase):
     def setUp(self) -> None:
         create_users()
         _, _, self.module, chapter, _ = BookFactory.create_default_structure()
-        text = {"type": "text_block", "value": {"text": "Hallo"}}
-        assignment = {
-            "type": "assignment",
-            "value": {"title": "Hello", "assignment": "Assignment"},
-        }
-        survey = {"type": "survey", "value": {"title": "Survey Title", "data": "null"}}
+        self.assignment = AssignmentFactory(assignment="Assignment", title="Hello")
+        survey = SurveyFactory(title="Survey Title")
+        rich_text = RichText("Hallo")
         self.content_block = ContentBlockFactory.create(
             parent=chapter,
             module=self.module,
             title="Another content block",
             type="task",
-            contents=[text, assignment, survey],
+            contents__0__text_block__text=rich_text,
+            contents__1__assignment__assignment_id=self.assignment,
+            contents__2__survey__survey_id=survey,
         )
-        self.assignment = Assignment.objects.first()
 
     def test_duplicate_entities(self):
         self.assertEqual(