diff --git a/endpoints/v2/blob.py b/endpoints/v2/blob.py
index e5632c6d2..f5cfb8601 100644
--- a/endpoints/v2/blob.py
+++ b/endpoints/v2/blob.py
@@ -7,7 +7,8 @@ from app import storage, app
 from data import model, database
 from digest import digest_tools
 from endpoints.v2 import v2_bp, require_repo_read, require_repo_write, get_input_stream
-from endpoints.v2.errors import BlobUnknown, BlobUploadInvalid, BlobUploadUnknown, Unsupported
+from endpoints.v2.errors import (BlobUnknown, BlobUploadInvalid, BlobUploadUnknown, Unsupported,
+                                 NameUnknown)
 from auth.jwt_auth import process_jwt_auth
 from endpoints.decorators import anon_protect
 from util.cache import cache_control
@@ -105,7 +106,12 @@ def _render_range(num_uploaded_bytes, with_bytes_prefix=True):
 def start_blob_upload(namespace, repo_name):
   location_name = storage.preferred_locations[0]
   new_upload_uuid, upload_metadata = storage.initiate_chunked_upload(location_name)
-  model.blob.initiate_upload(namespace, repo_name, new_upload_uuid, location_name, upload_metadata)
+
+  try:
+    model.blob.initiate_upload(namespace, repo_name, new_upload_uuid, location_name,
+                               upload_metadata)
+  except database.Repository.DoesNotExist:
+    raise NameUnknown()
 
   digest = request.args.get('digest', None)
   if digest is None: