diff --git a/sale_order_batch/models/sale_order.py b/sale_order_batch/models/sale_order.py
index 91f9a77..1fdf8bc 100644
--- a/sale_order_batch/models/sale_order.py
+++ b/sale_order_batch/models/sale_order.py
@@ -13,7 +13,7 @@ class SaleOrder(models.Model):
         """
         batch = self.env["sale.order.batch"].search([("state", "=", "open")], limit=1)
         if not batch:
-            batch = self.env["sale.order.batch"].create()
+            batch = self.env["sale.order.batch"].create({})
         for sale_order in self:
             if not sale_order.batch_id and sale_order.state in ["draft", "sent"]:
                 sale_order.batch_id = batch
diff --git a/sale_order_batch/models/sale_order_batch.py b/sale_order_batch/models/sale_order_batch.py
index 637b6e6..59afb0a 100644
--- a/sale_order_batch/models/sale_order_batch.py
+++ b/sale_order_batch/models/sale_order_batch.py
@@ -39,7 +39,7 @@ class SaleOrderBatch(models.Model):
         required=True,
         readonly=False,
         copy=False,
-        states={"closed": [("readonly", False)]},
+        states={"closed": [("readonly", True)]},
         help="Creation date of order batch,\nConfirmation date of confirmed orders.",
         default=fields.Datetime.now,
     )