diff --git a/htdocs/install/mysql/migration/5.0.0-6.0.0.sql b/htdocs/install/mysql/migration/5.0.0-6.0.0.sql
index 0b41cf739ef..f418a5e6a1f 100644
--- a/htdocs/install/mysql/migration/5.0.0-6.0.0.sql
+++ b/htdocs/install/mysql/migration/5.0.0-6.0.0.sql
@@ -346,6 +346,8 @@ ALTER TABLE llx_product_fournisseur_price_log ADD COLUMN multicurrency_tx	     d
 ALTER TABLE llx_product_fournisseur_price_log ADD COLUMN multicurrency_price	 double(24,8) DEFAULT NULL;
 ALTER TABLE llx_product_fournisseur_price_log ADD COLUMN multicurrency_price_ttc double(24,8) DEFAULT NULL;
 
+UPDATE TABLE llx_contrat set ref = rowid where ref is null or ref = '';
+
 create table llx_payment_various
 (
   rowid                 integer AUTO_INCREMENT PRIMARY KEY,