diff --git a/pandora/annotation/models.py b/pandora/annotation/models.py
index 477c12255..eb6874502 100644
--- a/pandora/annotation/models.py
+++ b/pandora/annotation/models.py
@@ -123,7 +123,8 @@ class Annotation(models.Model):
                                                             start=self.start,
                                                             end=self.end)
             if created:
-                self.clip.save()
+                clip = Clip.objects.get(pk=self.clip.pk)
+                clip.save()
 
         super(Annotation, self).save(*args, **kwargs)
 
diff --git a/pandora/clip/models.py b/pandora/clip/models.py
index 5f5bf85ff..33ac543cc 100644
--- a/pandora/clip/models.py
+++ b/pandora/clip/models.py
@@ -20,7 +20,7 @@ class Clip(models.Model):
 
     created = models.DateTimeField(auto_now_add=True)
     modified = models.DateTimeField(auto_now=True)
-    public_id = models.CharField(max_length=128, unique=True)
+    public_id = models.CharField(max_length=128, unique=True, null=True)
 
     item = models.ForeignKey('item.Item', related_name='clips')