diff --git a/django/views/admin/main.py b/django/views/admin/main.py
index 5a2732d152..210523a8bb 100644
--- a/django/views/admin/main.py
+++ b/django/views/admin/main.py
@@ -1048,7 +1048,7 @@ def delete_stage(request, app_label, module_name, object_id):
     if not request.user.has_perm(app_label + '.' + opts.get_delete_permission()):
         raise PermissionDenied
     try:
-        obj = mod.get_object(**{'%s__exact' % opts.pk.name: object_id})
+        obj = mod.get_object(pk=object_id)
     except ObjectDoesNotExist:
         raise Http404
 
@@ -1082,7 +1082,7 @@ def history(request, app_label, module_name, object_id):
         order_by=("action_time",), select_related=True)
     # If no history was found, see whether this object even exists.
     try:
-        obj = mod.get_object(**{'%s__exact' % opts.pk.name: object_id})
+        obj = mod.get_object(pk=object_id)
     except ObjectDoesNotExist:
         raise Http404
     t = template_loader.get_template('admin_object_history')