diff --git a/mrp_workorder_sequence/hooks.py b/mrp_workorder_sequence/hooks.py
index 52e2f89e4..c080cb29f 100644
--- a/mrp_workorder_sequence/hooks.py
+++ b/mrp_workorder_sequence/hooks.py
@@ -1,11 +1,19 @@
 # Copyright 2022 Camptocamp SA
 # License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl)
-from odoo import SUPERUSER_ID, api, tools
 
 
 def post_init_hook(cr, registry):
-    env = api.Environment(cr, SUPERUSER_ID, {})
-    all_workorders = env["mrp.workorder"].search([], order="production_id ASC, id ASC")
-    for _, workorders in tools.groupby(all_workorders, lambda w: w.production_id):
-        for seq, wo in enumerate(workorders, 1):
-            wo.sequence = seq
+    cr.execute(
+        """
+            UPDATE mrp_workorder
+            SET sequence = n.sequence
+            FROM (
+                SELECT
+                    id,
+                    ROW_NUMBER() OVER (PARTITION BY production_id) AS sequence
+                FROM mrp_workorder
+                ORDER BY production_id, id
+            ) AS n
+            WHERE mrp_workorder.id = n.id
+        """
+    )