diff --git a/django/db/models/query.py b/django/db/models/query.py
index 23d0bac6c8f..4d0d295e975 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -1180,7 +1180,7 @@ def delete_objects(seen_objs):
                 if field.rel and field.null and field.rel.to in seen_objs:
                     setattr(instance, field.attname, None)
 
-            setattr(instance, cls._meta.pk.attname, None)
             dispatcher.send(signal=signals.post_delete, sender=cls, instance=instance)
+            setattr(instance, cls._meta.pk.attname, None)
 
     transaction.commit_unless_managed()
diff --git a/tests/modeltests/signals/models.py b/tests/modeltests/signals/models.py
index d41142135e2..1fb73828bb5 100644
--- a/tests/modeltests/signals/models.py
+++ b/tests/modeltests/signals/models.py
@@ -54,7 +54,7 @@ Is updated
 pre_delete signal, Tom Smith
 instance.id is not None: True
 post_delete signal, Tom Smith
-instance.id is None: True
+instance.id is None: False
 
 >>> p2 = Person(first_name='James', last_name='Jones')
 >>> p2.id = 99999
@@ -73,7 +73,7 @@ Is created
 pre_delete signal, James Jones
 instance.id is not None: True
 post_delete signal, James Jones
-instance.id is None: True
+instance.id is None: False
 
 >>> Person.objects.all()
 [<Person: James Jones>]