diff --git a/htdocs/install/mysql/migration/6.0.0-7.0.0.sql b/htdocs/install/mysql/migration/6.0.0-7.0.0.sql
index 354bf0743bd..b8b1b15051c 100644
--- a/htdocs/install/mysql/migration/6.0.0-7.0.0.sql
+++ b/htdocs/install/mysql/migration/6.0.0-7.0.0.sql
@@ -717,4 +717,5 @@ ALTER TABLE llx_facture_rec_extrafields ADD INDEX idx_facture_rec_extrafields (f
 UPDATE llx_cronjob set entity = 1 where entity = 0 and label in ('RecurringInvoices', 'SendEmailsReminders');
 UPDATE llx_cronjob set entity = 0 where entity = 1 and label in ('PurgeDeleteTemporaryFilesShort', 'MakeLocalDatabaseDumpShort');
 
-ALTER TABLE llx_c_shipment_mode CHANGE COLUMN tracking tracking VARCHAR(255) DEFAULT NULL;
\ No newline at end of file
+-- VMYSQL4.3 ALTER TABLE llx_c_shipment_mode MODIFY COLUMN tracking varchar(255) NULL;
+-- VPGSQL8.2 ALTER TABLE llx_c_shipment_mode ALTER COLUMN tracking DROP NOT NULL;
diff --git a/htdocs/install/mysql/tables/llx_c_shipment_mode.sql b/htdocs/install/mysql/tables/llx_c_shipment_mode.sql
index b94936c7461..7945c9f9fb0 100644
--- a/htdocs/install/mysql/tables/llx_c_shipment_mode.sql
+++ b/htdocs/install/mysql/tables/llx_c_shipment_mode.sql
@@ -23,7 +23,7 @@ create table llx_c_shipment_mode
   code             varchar(30) NOT NULL,
   libelle          varchar(50) NOT NULL,
   description      text,
-  tracking         varchar(255) NOT NULL,
+  tracking         varchar(255) NULL,
   active           tinyint DEFAULT 0,
   module           varchar(32) NULL
 )ENGINE=innodb;