diff --git a/submissions/admin.py b/submissions/admin.py
index dfc3dff7b8c223034d8d13ac0136463d1d54be6d..0e394cedfb8da410dfbcda6c3c72047380a6b39e 100644
--- a/submissions/admin.py
+++ b/submissions/admin.py
@@ -63,6 +63,9 @@ admin.site.register(EditorialAssignment, EditorialAssignmentAdmin)
 class RefereeInvitationAdminForm(forms.ModelForm):
     submission = forms.ModelChoiceField(
         queryset=Submission.objects.order_by('-arxiv_identifier_w_vn_nr'))
+    referee = forms.ModelChoiceField(
+        required=False,
+        queryset=Contributor.objects.order_by('user__last_name'))
 
     class Meta:
         model = RefereeInvitation