diff --git a/htdocs/install/mysql/migration/10.0.0-11.0.0.sql b/htdocs/install/mysql/migration/10.0.0-11.0.0.sql
index b10ab3b9a85..4ec9fbdaffb 100644
--- a/htdocs/install/mysql/migration/10.0.0-11.0.0.sql
+++ b/htdocs/install/mysql/migration/10.0.0-11.0.0.sql
@@ -48,3 +48,5 @@ ALTER TABLE llx_facture_fourn DROP COLUMN total;
 
 ALTER TABLE llx_user ADD COLUMN iplastlogin         varchar(250);
 ALTER TABLE llx_user ADD COLUMN ippreviouslogin     varchar(250);
+
+ALTER TABLE llx_events ADD COLUMN prefix_session varchar(250) NULL;
diff --git a/htdocs/install/mysql/tables/llx_events.sql b/htdocs/install/mysql/tables/llx_events.sql
index f906cf0fcbd..c9f8f034a34 100644
--- a/htdocs/install/mysql/tables/llx_events.sql
+++ b/htdocs/install/mysql/tables/llx_events.sql
@@ -27,6 +27,7 @@ create table llx_events
   tms            timestamp,                   -- date creation/modification
   type           varchar(32)  NOT NULL,       -- action type
   entity         integer DEFAULT 1 NOT NULL,	-- multi company id
+  prefix_session varchar(255) NULL,				  -- prefix of session, obtained with dol_getprefix
   dateevent      datetime,                    -- date event
   fk_user        integer,                     -- id user
   description    varchar(250) NOT NULL,       -- full description of action