diff --git a/mysql/migration/2.1.0-2.2.0.sql b/mysql/migration/2.1.0-2.2.0.sql
index 8a778592857..2c551cb9643 100644
--- a/mysql/migration/2.1.0-2.2.0.sql
+++ b/mysql/migration/2.1.0-2.2.0.sql
@@ -37,6 +37,8 @@ alter table llx_adherent_type modify libelle          varchar(50) NOT NULL;
 
 -- Extention de la gestion des catégories
 alter table llx_categorie ADD type int not null default '0';
+-- V4 ALTER TABLE llx_categorie DROP INDEX uk_categorie_ref;
+ALTER TABLE llx_categorie ADD UNIQUE INDEX uk_categorie_ref (label,type);
 
 drop table if exists `llx_categorie_societe`;
 create table `llx_categorie_societe` (
@@ -658,5 +660,3 @@ ALTER TABLE `llx_osc_product` ADD UNIQUE KEY `fk_product` (`fk_product`);
 -- V4 ALTER TABLE llx_telephonie_societe_ligne ADD FOREIGN KEY (fk_soc_facture) REFERENCES llx_societe(rowid);
 -- V4 ALTER TABLE llx_telephonie_tarif_client ADD FOREIGN KEY (fk_client) REFERENCES llx_societe (rowid);
 -- fin du changement idp en rowid
-
--- V4 ALTER TABLE llx_categorie DROP INDEX uk_categorie_ref;
\ No newline at end of file
diff --git a/mysql/tables/llx_categorie.key.sql b/mysql/tables/llx_categorie.key.sql
new file mode 100644
index 00000000000..c1fd149571b
--- /dev/null
+++ b/mysql/tables/llx_categorie.key.sql
@@ -0,0 +1,20 @@
+-- ============================================================================
+-- Copyright (C) 2007 Laurent Destailleur  <eldy@users.sourceforge.net>
+--
+-- This program is free software; you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation; either version 2 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program; if not, write to the Free Software
+-- Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+--
+-- ============================================================================
+
+ALTER TABLE llx_categorie ADD UNIQUE INDEX uk_categorie_ref (label,type);