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 b5e80f43593..87053d8ccb7 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
@@ -67,3 +67,6 @@ insert into llx_c_action_trigger (code,label,description,elementtype,rang) value
 insert into llx_c_action_trigger (code,label,description,elementtype,rang) values ('EXPENSE_DELETE','Expense report deleted','Executed when an expense report is deleted','expensereport',204);
 
 ALTER TABLE llx_payment_salary ADD COLUMN fk_projet integer DEFAULT NULL after amount;
+
+ALTER TABLE llx_categorie ADD COLUMN ref_ext varchar(255);
+
diff --git a/htdocs/install/mysql/tables/llx_categorie.sql b/htdocs/install/mysql/tables/llx_categorie.sql
index fe2b03b2429..5493d2cfc8c 100644
--- a/htdocs/install/mysql/tables/llx_categorie.sql
+++ b/htdocs/install/mysql/tables/llx_categorie.sql
@@ -24,7 +24,8 @@ create table llx_categorie
 	rowid 		    integer AUTO_INCREMENT PRIMARY KEY,
 	entity          integer DEFAULT 1 NOT NULL,			-- multi company id
 	fk_parent		integer DEFAULT 0 NOT NULL,
-	label 		    varchar(180) NOT NULL,				-- category name
+	label 		    varchar(180) NOT NULL,				-- category ref/name
+	ref_ext			varchar(255),						-- reference into an external system (not used by dolibarr)
 	type	        tinyint DEFAULT 1 NOT NULL,			-- category type (product, supplier, customer, member)
 	description 	text,								-- description of the category
     color           varchar(8),                         -- color