diff --git a/sql/swh-vault-schema.sql b/sql/swh-vault-schema.sql
index 4a1de0a..5b1bc1a 100644
--- a/sql/swh-vault-schema.sql
+++ b/sql/swh-vault-schema.sql
@@ -1,41 +1,41 @@
 create table dbversion
 (
   version     int primary key,
   release     timestamptz not null,
   description text not null
 );
 comment on table dbversion is 'Schema update tracking';
 insert into dbversion (version, release, description)
        values (1, now(), 'Initial version');
 
 create domain obj_hash as bytea;
 
 create type cook_type as enum ('directory', 'revision_gitfast');
 comment on type cook_type is 'Type of the requested bundle';
 
 create type cook_status as enum ('new', 'pending', 'done');
 comment on type cook_status is 'Status of the cooking';
 
 create table vault_bundle (
   id bigserial primary key,
 
   type cook_type not null,  -- requested cooking type
   object_id obj_hash not null,  -- requested object ID
 
-  task_uuid varchar(128) not null,  -- celery UUID of the cooking task
+  task_uuid uuid not null,  -- celery UUID of the cooking task
   task_status cook_status not null default 'new',  -- status of the task
 
   ts_created timestamptz not null default now(),  -- timestamp of creation
   ts_done timestamptz,  -- timestamp of the cooking result
   ts_last_access timestamptz not null default now(),  -- last access
 
   progress_msg text, -- progress message
 
   unique(type, object_id)
 );
 
 create table vault_notif_email (
   id bigserial primary key,
   email text not null,              -- e-mail to notify
   bundle_id bigint not null references vault_bundle(id)
 );