diff --git a/sql/updates/27.sql b/sql/updates/27.sql
index f7d2194..23045be 100644
--- a/sql/updates/27.sql
+++ b/sql/updates/27.sql
@@ -1,29 +1,29 @@
 -- SWH DB schema upgrade
 -- from_version: 26
 -- to_version: 27
 -- description: Clean up no longer used stored procedure
 
 insert into dbversion (version, release, description)
        values (27, now(), 'Work In Progress');
 
-delete function swh_scheduler_peek_ready_tasks (text, timestamptz, bigint, bigint);
-delete function swh_scheduler_peek_priority_tasks (text, timestamptz, bigint);
+drop function swh_scheduler_peek_ready_tasks (text, timestamptz, bigint, bigint);
+drop function swh_scheduler_peek_priority_tasks (text, timestamptz, bigint);
 -- delete old signature function
-delete function swh_scheduler_grab_ready_tasks (text, timestamptz, bigint, bigint);
+drop function swh_scheduler_grab_ready_tasks (text, timestamptz, bigint, bigint);
 
 create or replace function swh_scheduler_grab_ready_tasks (task_type text, ts timestamptz default now(),
                                                            num_tasks bigint default NULL)
   returns setof task
   language sql
 as $$
   update task
     set status='next_run_scheduled'
     from (
         select id from swh_scheduler_peek_no_priority_tasks(task_type, ts, num_tasks)
     ) next_tasks
     where task.id = next_tasks.id
   returning task.*;
 $$;
 
 comment on function swh_scheduler_grab_ready_tasks (text, timestamptz, bigint)
 is 'Grab (no priority) tasks ready for scheduling and change their status';