diff --git a/htdocs/install/mysql/tables/llx_element_tag.key.sql b/htdocs/install/mysql/tables/llx_element_tag.key.sql
new file mode 100644
index 00000000000..d3a0b38afa9
--- /dev/null
+++ b/htdocs/install/mysql/tables/llx_element_tag.key.sql
@@ -0,0 +1,21 @@
+-- ============================================================================
+-- Copyright (C) 2021 Maxime Kohlhaas       <support@atm-consulting.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 <https://www.gnu.org/licenses/>.
+--
+-- ============================================================================
+
+ALTER TABLE llx_element_tag ADD UNIQUE INDEX idx_element_tag_uk (fk_categorie, fk_element);
+
+ALTER TABLE llx_element_tag ADD CONSTRAINT fk_element_tag_categorie_rowid FOREIGN KEY (fk_categorie) REFERENCES llx_categorie (rowid);
diff --git a/htdocs/install/mysql/tables/llx_element_tag.sql b/htdocs/install/mysql/tables/llx_element_tag.sql
new file mode 100644
index 00000000000..d43ced98130
--- /dev/null
+++ b/htdocs/install/mysql/tables/llx_element_tag.sql
@@ -0,0 +1,25 @@
+-- ============================================================================
+-- Copyright (C) 2021 Maxime Kohlhaas       <support@atm-consulting.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 <https://www.gnu.org/licenses/>.
+--
+-- ============================================================================
+
+create table llx_element_tag
+(
+  rowid integer AUTO_INCREMENT PRIMARY KEY,
+  fk_categorie  integer NOT NULL,
+  fk_element  integer NOT NULL,
+  import_key    varchar(14)
+)ENGINE=innodb;