diff --git a/tools/auditancestry.py b/tools/auditancestry.py
index 920719880..c9c350a79 100644
--- a/tools/auditancestry.py
+++ b/tools/auditancestry.py
@@ -96,6 +96,16 @@ def resolve_or_create(repo, docker_image_id, new_ancestry):
         raise RuntimeError()
 
 
+def all_ancestors_exist(ancestors):
+  if not ancestors:
+    return True
+
+  found_count = len(list(Image
+    .select()
+    .where(Image.id << ancestors)))
+  return found_count == len(ancestors)
+
+
 cant_fix = []
 for img in query:
   try:
@@ -111,7 +121,7 @@ for img in query:
       ancestor_dbids = [int(anc_id) 
                         for anc_id in img.ancestors.split('/')[1:-1]]
 
-      if len(full_ancestry) != len(ancestor_dbids):
+      if len(full_ancestry) != len(ancestor_dbids) or not all_ancestors_exist(ancestor_dbids):
         logger.error('Image has incomplete ancestry: %s, %s, %s, %s' %
                      (img.id, img.docker_image_id, full_ancestry,
                       ancestor_dbids))