diff --git a/htdocs/install/mysql/migration/15.0.0-16.0.0.sql b/htdocs/install/mysql/migration/15.0.0-16.0.0.sql
index 8eb37fb4f31..26e424fca35 100644
--- a/htdocs/install/mysql/migration/15.0.0-16.0.0.sql
+++ b/htdocs/install/mysql/migration/15.0.0-16.0.0.sql
@@ -30,7 +30,7 @@
 -- -- VPGSQL8.2 SELECT dol_util_rebuild_sequences();
 
 
-ALTER TABLE llx_holiday ADD COLUMN nb_open_day double(24,8)     DEFAULT 0;
+ALTER TABLE llx_holiday ADD COLUMN nb_open_day double(24,8) DEFAULT NULL;
 
 -- Missing in v15 or lower
 
diff --git a/htdocs/install/mysql/tables/llx_holiday.sql b/htdocs/install/mysql/tables/llx_holiday.sql
index 54d5525bd54..be468bd32a5 100644
--- a/htdocs/install/mysql/tables/llx_holiday.sql
+++ b/htdocs/install/mysql/tables/llx_holiday.sql
@@ -31,11 +31,11 @@ description    VARCHAR( 255 ) NOT NULL,
 date_debut     DATE NOT NULL,
 date_fin       DATE NOT NULL,
 halfday        integer DEFAULT 0,				-- 0=start morning and end afternoon, -1=start afternoon end afternoon, 1=start morning and end morning, 2=start afternoon and end morning
-nb_open_day    double(24,8)     DEFAULT 0,  -- denormalized number of open days of holiday. Not always set. More reliable when re-calculated with num_open_days(date_debut, date_fin, halfday).
-statut         integer NOT NULL DEFAULT 1,
-fk_validator   integer NOT NULL,				-- who should approve
-date_valid     DATETIME DEFAULT NULL,			-- date approval (both date valid and date_approval)
-fk_user_valid  integer DEFAULT NULL,			-- user approval (both user valid and user that approved)
+nb_open_day    double(24,8) DEFAULT NULL,       -- denormalized number of open days of holiday. Not always set. More reliable when re-calculated with num_open_days(date_debut, date_fin, halfday).
+statut         integer NOT NULL DEFAULT 1,      -- status of leave request
+fk_validator   integer NOT NULL,				-- who should approve the leave
+date_valid     DATETIME DEFAULT NULL,			-- date approval (currently both date valid and date_approval)
+fk_user_valid  integer DEFAULT NULL,			-- user approval (currently both user valid and user that approved)
 date_approve   DATETIME DEFAULT NULL,			-- date approval (not used yet)
 fk_user_approve integer DEFAULT NULL,			-- user approval (not used yet)
 date_refuse    DATETIME DEFAULT NULL,