diff --git a/data/model/oci/tag.py b/data/model/oci/tag.py
index b90efc1f4..0a7706c96 100644
--- a/data/model/oci/tag.py
+++ b/data/model/oci/tag.py
@@ -78,10 +78,11 @@ def list_repository_tag_history(repository_id, page, page_size, specific_tag_nam
                                 active_tags_only=False):
   """ Returns a tuple of the full set of tags found in the specified repository, including those
       that are no longer alive (unless active_tags_only is True), and whether additional tags exist.
-      If specific_tag_name is given, the tags are further filtered by name.
+      If specific_tag_name is given, the tags are further filtered by name. Note that the
+      returned Manifest will not contain the manifest contents.
   """
   query = (Tag
-           .select(Tag, Manifest)
+           .select(Tag, Manifest.id, Manifest.digest, Manifest.media_type)
            .join(Manifest)
            .where(Tag.repository == repository_id)
            .order_by(Tag.lifetime_start_ms.desc(), Tag.name)
diff --git a/data/registry_model/datatypes.py b/data/registry_model/datatypes.py
index f3bbb543b..b0352cce2 100644
--- a/data/registry_model/datatypes.py
+++ b/data/registry_model/datatypes.py
@@ -217,9 +217,12 @@ class Manifest(datatype('Manifest', ['digest', 'media_type', 'internal_manifest_
     if manifest is None:
       return None
 
+    # NOTE: `manifest_bytes` will be None if not selected by certain join queries.
+    manifest_bytes = (Bytes.for_string_or_unicode(manifest.manifest_bytes)
+                      if manifest.manifest_bytes is not None else None)
     return Manifest(db_id=manifest.id,
                     digest=manifest.digest,
-                    internal_manifest_bytes=Bytes.for_string_or_unicode(manifest.manifest_bytes),
+                    internal_manifest_bytes=manifest_bytes,
                     media_type=ManifestTable.media_type.get_name(manifest.media_type_id),
                     inputs=dict(legacy_image=legacy_image, tag_manifest=False))
 
@@ -245,6 +248,7 @@ class Manifest(datatype('Manifest', ['digest', 'media_type', 'internal_manifest_
 
   def get_parsed_manifest(self, validate=True):
     """ Returns the parsed manifest for this manifest. """
+    assert self.internal_manifest_bytes
     return parse_manifest_from_bytes(self.internal_manifest_bytes, self.media_type,
                                      validate=validate)
 
diff --git a/endpoints/api/tag.py b/endpoints/api/tag.py
index 280853fdf..b6ce4e0ad 100644
--- a/endpoints/api/tag.py
+++ b/endpoints/api/tag.py
@@ -41,9 +41,6 @@ def _tag_dict(tag):
     if tag.manifest:
       tag_info['is_manifest_list'] = tag.manifest.is_manifest_list
 
-      if 'size' not in tag_info:
-        tag_info['size'] = tag.manifest.layers_compressed_size
-
   if tag.lifetime_start_ts > 0:
     last_modified = format_date(datetime.utcfromtimestamp(tag.lifetime_start_ts))
     tag_info['last_modified'] = last_modified