diff --git a/S1/waitinglists/admin.py b/S1/waitinglists/admin.py
index c0df42c..4399bf4 100644
--- a/S1/waitinglists/admin.py
+++ b/S1/waitinglists/admin.py
@@ -6,7 +6,10 @@
 
 
 class SessionAdmin(admin.ModelAdmin):
-    readonly_fields = ("attendance_done", "open_signup")
+    def get_readonly_fields(self, request, obj=None):
+        if request.user.groups.filter(name="Mentor").exists():
+            return ("attendance_done", "open_signup")
+        return super().get_readonly_fields(request, obj)
 
     def formfield_for_foreignkey(self, db_field, request, **kwargs):
         if db_field.name == "mentor":