diff --git a/pandora/annotation/models.py b/pandora/annotation/models.py
index d4a80946c..426294372 100644
--- a/pandora/annotation/models.py
+++ b/pandora/annotation/models.py
@@ -48,6 +48,12 @@ class Annotation(models.Model):
     def set_public_id(self):
         if self.id:
             public_id = Annotation.objects.filter(item=self.item, id__lt=self.id).count() + 1
+            if public_id > 1:
+                previous = Annotation.objects.filter(item=self.item,
+                    id__lt=self.id).order_by('-id')[0]
+                if not previous.public_id:
+                    previous.set_public_id()
+                public_id = ox.fromAZ(previous.public_id.split('/')[-1]) + 1
             self.public_id = "%s/%s" % (self.item.itemId, ox.toAZ(public_id))
             Annotation.objects.filter(id=self.id).update(public_id=self.public_id)