diff --git a/atlas/filters.py b/atlas/filters.py
index 529cc1c3..0066b5e9 100755
--- a/atlas/filters.py
+++ b/atlas/filters.py
@@ -21,7 +21,7 @@ class CaseFilter(django_filters.FilterSet):
         queryset=get_authors, null_label="No author"
     )
     differential = django_filters.ModelMultipleChoiceFilter(
-        field_name="differential__differentialset__condition",
+        field_name="differential__differential_set__condition",
         #to_field_name="differential",
         queryset=Condition.objects.all(),
     )