diff --git a/atlas/models.py b/atlas/models.py
index bab560aa..efc3e2ac 100644
--- a/atlas/models.py
+++ b/atlas/models.py
@@ -269,7 +269,7 @@ class Case(models.Model):
 
     notes = GenericRelation(QuestionNote)
 
-    previous_case = models.OneToOneField("Case", on_delete=models.SET_NULL, null=True, related_name="next_case")
+    previous_case = models.OneToOneField("Case", on_delete=models.SET_NULL, null=True, related_name="next_case", blank=True)
 
     # question_file = models.FileField(upload_to=question_file_directory_path, blank=True, null=True)