diff --git a/htdocs/install/mysql/migration/3.6.0-3.7.0.sql b/htdocs/install/mysql/migration/3.6.0-3.7.0.sql
index 2dc79d20c3f..0ad0d3df04d 100644
--- a/htdocs/install/mysql/migration/3.6.0-3.7.0.sql
+++ b/htdocs/install/mysql/migration/3.6.0-3.7.0.sql
@@ -961,6 +961,7 @@ CREATE TABLE llx_holiday_types (
 );
 
 -- Change on table c_civilite
+DROP INDEX uk_c_civilite ON llx_c_civilite;
 ALTER TABLE llx_c_civilite RENAME TO llx_c_civility;
 ALTER TABLE llx_c_civility CHANGE civilite label VARCHAR(50);
 ALTER TABLE llx_c_civility ADD UNIQUE INDEX uk_c_civility(code);