diff --git a/django_summernote/models.py b/django_summernote/models.py
index 61e4400f..9c55fbd5 100644
--- a/django_summernote/models.py
+++ b/django_summernote/models.py
@@ -1,11 +1,12 @@
 from django.db import models
-from django_summernote.utils import get_attachment_storage, get_attachment_upload_to
 
+from django_summernote.utils import get_attachment_storage, get_attachment_upload_to
 
 __all__ = ['AbstractAttachment', 'Attachment', ]
 
 
 class AbstractAttachment(models.Model):
+    id = models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name="ID")
     name = models.CharField(max_length=255, null=True, blank=True, help_text="Defaults to filename, if left blank")
     file = models.FileField(
         upload_to=get_attachment_upload_to(),