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 dd0aba11632..6dc2521ca5d 100755
--- a/htdocs/install/mysql/migration/3.6.0-3.7.0.sql
+++ b/htdocs/install/mysql/migration/3.6.0-3.7.0.sql
@@ -1106,6 +1106,7 @@ ALTER TABLE llx_projet_task_time ADD INDEX idx_projet_task_time_datehour (task_d
 ALTER TABLE llx_projet_task MODIFY COLUMN duration_effective real DEFAULT 0 NULL;
 ALTER TABLE llx_projet_task MODIFY COLUMN planned_workload real DEFAULT 0 NULL;
   
+-- VPGSQL8.2 ALTER TABLE llx_projet_task ALTER COLUMN planned_workload DROP NOT NULL;
 
 -- add extrafield on ficheinter lines
 CREATE TABLE llx_fichinterdet_extrafields
diff --git a/htdocs/install/mysql/migration/3.7.0-3.8.0.sql b/htdocs/install/mysql/migration/3.7.0-3.8.0.sql
index c997d511fdb..63bc1a8d7a3 100755
--- a/htdocs/install/mysql/migration/3.7.0-3.8.0.sql
+++ b/htdocs/install/mysql/migration/3.7.0-3.8.0.sql
@@ -110,6 +110,7 @@ ALTER TABLE llx_projet_task_time ADD COLUMN task_date_withhour integer DEFAULT 0
 ALTER TABLE llx_projet_task MODIFY COLUMN duration_effective real DEFAULT 0 NULL;
 ALTER TABLE llx_projet_task MODIFY COLUMN planned_workload real DEFAULT 0 NULL;
 
+-- VPGSQL8.2 ALTER TABLE llx_projet_task ALTER COLUMN planned_workload DROP NOT NULL;
 
 ALTER TABLE llx_commande_fournisseur MODIFY COLUMN date_livraison datetime;
 
diff --git a/htdocs/install/mysql/migration/5.0.0-6.0.0.sql b/htdocs/install/mysql/migration/5.0.0-6.0.0.sql
index d18da18ac6a..faf196a9802 100644
--- a/htdocs/install/mysql/migration/5.0.0-6.0.0.sql
+++ b/htdocs/install/mysql/migration/5.0.0-6.0.0.sql
@@ -467,6 +467,8 @@ DELETE FROM llx_categorie_project WHERE fk_categorie NOT IN (SELECT rowid FROM l
 
 ALTER TABLE llx_inventory ADD COLUMN ref varchar(48);
 
+-- VPGSQL8.2 ALTER TABLE llx_projet_task ALTER COLUMN planned_workload DROP NOT NULL;
+
 CREATE TABLE llx_loan_schedule
 (
   rowid				integer AUTO_INCREMENT PRIMARY KEY,