diff --git a/djangoldp_notification/models.py b/djangoldp_notification/models.py
index 3adfe0d..ba1ca87 100644
--- a/djangoldp_notification/models.py
+++ b/djangoldp_notification/models.py
@@ -54,11 +54,12 @@ class Subscription(Model):
 # --- SUBSCRIPTION SYSTEM ---
 @receiver(post_save, dispatch_uid="callback_notif")
 def send_notification(sender, instance, **kwargs):
-    if sender != Notification and isinstance(sender, Model):
+    if sender != Notification and issubclass(sender, Model):
         threads = []
-        url = settings.BASE_URL + Model.resource_id(instance) + '/'
-        for subscription in Subscription.objects.filter(object=url):
-            process = Thread(target=send_request, args=[subscription.inbox, url])
+        urlContainer = settings.BASE_URL + Model.container_id(instance)
+        urlResource = settings.BASE_URL + Model.resource_id(instance)
+        for subscription in Subscription.objects.filter(models.Q(object=urlResource)|models.Q(object=urlContainer)):
+            process = Thread(target=send_request, args=[subscription.inbox, urlResource])
             process.start()
             threads.append(process)