diff --git a/htdocs/install/upgrade2.php b/htdocs/install/upgrade2.php
index c49f7c706ce..08055c71d49 100644
--- a/htdocs/install/upgrade2.php
+++ b/htdocs/install/upgrade2.php
@@ -4567,8 +4567,8 @@ function migrate_productlot_path()
 			}
 
 			if ($dir) {
-				$lot->id = $obj->rowid;
-				$lot->ref = $obj->rowid;		// No ref for the moment
+				$lot->id = (int) $obj->rowid;
+				$lot->ref = (string) $obj->rowid;		// No ref for the moment
 				$lot->batch = $obj->batch;
 				$lot->entity = $obj->entity;
 				$lot->fk_product = $obj->fk_product;