diff --git a/script/odoo/migration/fix_migration_odoo130_to_odoo140.sql b/script/odoo/migration/fix_migration_odoo130_to_odoo140.sql
new file mode 100644
index 0000000..cde9856
--- /dev/null
+++ b/script/odoo/migration/fix_migration_odoo130_to_odoo140.sql
@@ -0,0 +1,39 @@
+-- © 2021-2026 TechnoLibre (http://www.technolibre.ca)
+-- License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl)
+--
+-- Odoo 13.0 -> 14.0 : hand the « group_fiscal_year » security group over to
+-- the module that owns it in 14.0.
+--
+-- In 13.0 the group « Allow to define fiscal years of more or less than a
+-- year » is declared by the core « account » module, so the database holds it
+-- as account.group_fiscal_year. In 14.0 core account no longer declares it and
+-- om_account_accountant (odoomates) does. During the upgrade that module finds
+-- no XML id of its own, tries to CREATE the group, and hits:
+--
+--   duplicate key value violates unique constraint "res_groups_name_uniq"
+--   Key (category_id, name)=(9, Allow to define fiscal years ...) already exists
+--
+-- Renaming the XML id makes Odoo UPDATE the existing row instead of creating a
+-- duplicate. The record id is untouched, so any user assignment, access right
+-- or record rule pointing at the group survives.
+--
+-- Runs through psql, not the Odoo shell: at this point the database is still
+-- 13.0 and loading it with the 14.0 registry is exactly what fails.
+
+UPDATE ir_model_data
+   SET module = 'om_account_accountant'
+ WHERE model = 'res.groups'
+   AND module = 'account'
+   AND name = 'group_fiscal_year'
+   -- Only when that module is actually part of this database.
+   AND EXISTS (
+        SELECT 1 FROM ir_module_module
+         WHERE name = 'om_account_accountant'
+           AND state IN ('installed', 'to upgrade', 'to install')
+   )
+   -- Idempotent: do nothing if the target XML id already exists.
+   AND NOT EXISTS (
+        SELECT 1 FROM ir_model_data
+         WHERE module = 'om_account_accountant'
+           AND name = 'group_fiscal_year'
+   );
diff --git a/script/todo/todo_upgrade.py b/script/todo/todo_upgrade.py
index b351903..cded711 100755
--- a/script/todo/todo_upgrade.py
+++ b/script/todo/todo_upgrade.py
@@ -1622,15 +1622,33 @@ class TodoUpgrade:
 
             if not lst_fix_migration_odoo[index]:
                 print("")
-                file_path_fix_migration = os.path.join(
-                    "script",
-                    "odoo",
-                    "migration",
-                    f"fix_migration_odoo{(next_version-1)*10}_to_odoo{next_version*10}.py",
+                stem = os.path.join(
+                    PATH_MIGRATION_GLOBAL,
+                    f"fix_migration_odoo{(next_version - 1) * 10}"
+                    f"_to_odoo{next_version * 10}",
                 )
-                if os.path.exists(file_path_fix_migration):
+                # Two flavours. « .sql » runs through psql: no Odoo registry,
+                # so it works on a database not yet migrated -- exactly when
+                # loading it with the TARGET version's code would fail. « .py »
+                # is piped into the Odoo shell when the ORM is really needed.
+                file_path_fix_migration = ""
+                cmd_fix_migration = ""
+                if os.path.exists(f"{stem}.sql"):
+                    file_path_fix_migration = f"{stem}.sql"
+                    cmd_fix_migration = (
+                        f"psql -v ON_ERROR_STOP=1 -d {database_name_upgrade}"
+                        f" -f ./{file_path_fix_migration}"
+                    )
+                elif os.path.exists(f"{stem}.py"):
+                    file_path_fix_migration = f"{stem}.py"
+                    cmd_fix_migration = (
+                        f"cat ./{file_path_fix_migration} |"
+                        f" ./odoo{next_version}.0/odoo/odoo-bin shell"
+                        f" -d {database_name_upgrade}"
+                    )
+                if file_path_fix_migration:
                     status, cmd_executed = self.todo_upgrade_execute(
-                        f"cat ./{file_path_fix_migration} | ./odoo{next_version}.0/odoo/odoo-bin shell -d {database_name_upgrade}",
+                        cmd_fix_migration,
                         single_source_odoo=True,
                     )