diff --git a/htdocs/install/mysql/tables/llx_contrat_extrafields.key.sql b/htdocs/install/mysql/tables/llx_contrat_extrafields.key.sql
new file mode 100644
index 0000000000000000000000000000000000000000..277520d7c2e824f1fa65a757cceee38b3b0751de
--- /dev/null
+++ b/htdocs/install/mysql/tables/llx_contrat_extrafields.key.sql
@@ -0,0 +1,20 @@
+-- ===================================================================
+-- Copyright (C) 2013 Charles-Fr BENKE	<charles.fr@benke.fr>
+--
+-- 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 3 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, see <http://www.gnu.org/licenses/>.
+--
+-- ===================================================================
+
+
+ALTER TABLE llx_contrat_extrafields ADD INDEX idx_contrat_extrafields (fk_object);