diff --git a/advlabdb/assistantModelViews.py b/advlabdb/assistantModelViews.py
index cc571a2..3d5fa92 100644
--- a/advlabdb/assistantModelViews.py
+++ b/advlabdb/assistantModelViews.py
@@ -125,16 +125,16 @@ class AssistantExperimentMarkView(SecureAssistantModelView):
         )
 
     def update_model(self, form, model):
-        if (form.oral_mark and form.oral_mark.data != model.oral_mark) or (
-            form.protocol_mark and form.protocol_mark.data != model.protocol_mark
+        if (form.oral_mark is not None and form.oral_mark.data != model.oral_mark) or (
+            form.protocol_mark is not None and form.protocol_mark.data != model.protocol_mark
         ):
             model.assistant = current_user.assistant
 
-            ret = super().update_model(form, model)
+            updateSuccessful = super().update_model(form, model)
 
             model.part_student.checkThenSetFinalPartMark()
 
-            return ret
+            return updateSuccessful
         else:
             # Nothing changed
             return True