diff --git a/data/model/tag.py b/data/model/tag.py
index dbff7ff73..d4c89c153 100644
--- a/data/model/tag.py
+++ b/data/model/tag.py
@@ -612,7 +612,13 @@ def get_possibly_expired_tag(namespace, repo_name, tag_name):
 
 def associate_generated_tag_manifest(namespace, repo_name, tag_name, manifest, storage_id_map):
   tag = get_active_tag(namespace, repo_name, tag_name)
-  return _create_manifest(tag, manifest, storage_id_map)
+  try:
+    manifest = TagManifest.get(digest=manifest.digest)
+    manifest.tag = tag
+    manifest.save()
+    return manifest, False
+  except TagManifest.DoesNotExist:
+    return _create_manifest(tag, manifest, storage_id_map), True
 
 
 def _create_manifest(tag, manifest, storage_id_map):
@@ -639,9 +645,20 @@ def _create_manifest(tag, manifest, storage_id_map):
 def populate_manifest(repository, manifest, legacy_image, storage_ids):
   """ Populates the rows for the manifest, including its blobs and legacy image. """
   media_type = Manifest.media_type.get_id(manifest.media_type)
+
+  # Check for an existing manifest. If present, return it.
+  try:
+    return Manifest.get(repository=repository, digest=manifest.digest)
+  except Manifest.DoesNotExist:
+    pass
+
   with db_transaction():
-    manifest_row = Manifest.create(digest=manifest.digest, repository=repository,
-                                   manifest_bytes=manifest.bytes, media_type=media_type)
+    try:
+      manifest_row = Manifest.create(digest=manifest.digest, repository=repository,
+                                     manifest_bytes=manifest.bytes, media_type=media_type)
+    except IntegrityError:
+      return Manifest.get(repository=repository, digest=manifest.digest)
+
     ManifestLegacyImage.create(manifest=manifest_row, repository=repository, image=legacy_image)
 
     blobs_to_insert = [dict(manifest=manifest_row, repository=repository,