diff --git a/server/vbv_lernwelt/competence/graphql/queries.py b/server/vbv_lernwelt/competence/graphql/queries.py
index fe3f2442..c94e7d6d 100644
--- a/server/vbv_lernwelt/competence/graphql/queries.py
+++ b/server/vbv_lernwelt/competence/graphql/queries.py
@@ -37,7 +37,9 @@ class CompetenceCertificateQuery(object):
             course_session_user = CourseSessionUser.objects.filter(
                 user__id=user_id
             ).first()
-            if not can_view_profile(info.context.user, course_session_user):
+            if course_session_user is None or not can_view_profile(
+                info.context.user, course_session_user
+            ):
                 return None
 
         setattr(info.context, "assignment_user_ids", user_ids)  # noqa: B010