diff --git a/htdocs/install/mysql/migration/8.0.0-9.0.0.sql b/htdocs/install/mysql/migration/8.0.0-9.0.0.sql
index 8e9d82c5fd1..966058e88d7 100644
--- a/htdocs/install/mysql/migration/8.0.0-9.0.0.sql
+++ b/htdocs/install/mysql/migration/8.0.0-9.0.0.sql
@@ -266,8 +266,12 @@ CREATE TABLE llx_pos_cash_fence(
 UPDATE llx_const set name = 'PRELEVEMENT_END_TO_END' where name = 'END_TO_END';
 UPDATE llx_const set name = 'PRELEVEMENT_USTRD' where name = 'USTRD';
 
--- Delete duplicate accounting account not used
 
+-- Delete duplicate accounting account, but only if not used
+DROP TABLE tmp_llx_accouting_account;
+CREATE TABLE tmp_llx_accouting_account AS SELECT MIN(rowid) as MINID, account_number, entity, fk_pcg_version, count(*) AS NB FROM llx_accounting_account group BY account_number, entity, fk_pcg_version HAVING count(*) >= 2 order by account_number, entity, fk_pcg_version;
+--SELECT * from tmp_llx_accouting_account;
+DELETE from llx_accounting_account where rowid in (select minid from tmp_llx_accouting_account where minid NOT IN (SELECT fk_code_ventilation from llx_facturedet) AND minid NOT IN (SELECT fk_code_ventilation from llx_facture_fourn_det) AND minid NOT IN (SELECT fk_code_ventilation from llx_expensereport_det))
 
 
 ALTER TABLE llx_accounting_account DROP INDEX uk_accounting_account;