diff --git a/install-dev/data/db_structure.sql b/install-dev/data/db_structure.sql
index 7a3dc0e9d..0dc3fd39e 100644
--- a/install-dev/data/db_structure.sql
+++ b/install-dev/data/db_structure.sql
@@ -542,7 +542,7 @@ CREATE TABLE `PREFIX_customer` (
   `passwd` varchar(32) NOT NULL,
   `last_passwd_gen` timestamp NOT NULL default CURRENT_TIMESTAMP,
   `birthday` date default NULL,
-	`account_number` varchar(128) NOT NULL,
+	`account_number` varchar(128) NULL,
   `newsletter` tinyint(1) unsigned NOT NULL default '0',
   `ip_registration_newsletter` varchar(15) default NULL,
   `newsletter_date_add` datetime default NULL,
diff --git a/install-dev/upgrade/sql/1.5.0.7.sql b/install-dev/upgrade/sql/1.5.0.7.sql
index 913598bb4..45c927a51 100644
--- a/install-dev/upgrade/sql/1.5.0.7.sql
+++ b/install-dev/upgrade/sql/1.5.0.7.sql
@@ -32,7 +32,7 @@ INSERT INTO `PREFIX_carrier_tax_rules_group_shop` (`id_carrier`, `id_tax_rules_g
 	(SELECT `id_carrier`, `id_tax_rules_group`, `id_shop` FROM `PREFIX_carrier`, `PREFIX_shop`);
 ALTER TABLE `PREFIX_carrier` DROP `id_tax_rules_group`;
 
-ALTER TABLE `PREFIX_customer` ADD `account_number` VARCHAR(128) NOT NULL AFTER `birthday`;
+ALTER TABLE `PREFIX_customer` ADD `account_number` VARCHAR(128) NULL AFTER `birthday`;
 
 ALTER TABLE  `PREFIX_product_shop` ADD  `id_category_default` INT( 11 ) UNSIGNED DEFAULT NULL;