diff --git a/product_contract/models/sale_order.py b/product_contract/models/sale_order.py
index 70835795c..680505f0a 100644
--- a/product_contract/models/sale_order.py
+++ b/product_contract/models/sale_order.py
@@ -83,15 +83,8 @@ class SaleOrder(models.Model):
         contract_model = self.env["contract.contract"]
         contracts = []
         for rec in self.filtered("is_contract"):
-            line_to_create_contract = rec.order_line.filtered(
-                lambda r: not r.contract_id and r.is_contract
-            )
-            line_to_update_contract = rec.order_line.filtered(
-                lambda r: r.contract_id
-                and r.is_contract
-                and r
-                not in r.contract_id.contract_line_ids.mapped("sale_order_line_id")
-            )
+            line_to_create_contract = rec._get_line_to_create_contract()
+            line_to_update_contract = rec._get_line_to_update_contract()
             contract_templates = self.env["contract.template"]
             for order_line in line_to_create_contract:
                 contract_template = order_line.product_id.with_company(
diff --git a/product_contract/models/sale_order_line.py b/product_contract/models/sale_order_line.py
index 0a4a190d4..ed9e91347 100644
--- a/product_contract/models/sale_order_line.py
+++ b/product_contract/models/sale_order_line.py
@@ -141,8 +141,8 @@ class SaleOrderLine(models.Model):
             rec.date_end = rec._get_date_end() if rec.date_start else False
 
     @api.onchange("product_id")
-    def onchange_product(self):
-        super().onchange_product()
+    def product_id_change(self):
+        super().product_id_change()
         for rec in self:
             if rec.product_id.is_contract:
                 rec.is_contract = True
@@ -270,7 +270,7 @@ class SaleOrderLine(models.Model):
                     )
 
     @api.constrains("product_id", "contract_id")
-    def _check_contract_sale_contract_template(self):
+    def _check_contract_sale_line_is_contract(self):
         for rec in self:
             if rec.is_contract and not rec.product_id.is_contract:
                 raise ValidationError(
diff --git a/product_contract/tests/test_sale_order.py b/product_contract/tests/test_sale_order.py
index 804863f99..f7c31380c 100644
--- a/product_contract/tests/test_sale_order.py
+++ b/product_contract/tests/test_sale_order.py
@@ -65,8 +65,15 @@ class TestSaleOrder(SavepointCase):
         cls.order_line1 = cls.sale.order_line.filtered(
             lambda l: l.product_id == cls.product1
         )
+
         cls.order_line1.date_start = "2018-01-01"
         cls.order_line1.product_uom_qty = 12
+        cls.order_line1.product_id_change()
+        cls.order_line2 = cls.sale.order_line.filtered(
+            lambda l: l.product_id == cls.product2
+        )
+        cls.order_line2.product_id_change()
+
         pricelist = cls.sale.partner_id.property_product_pricelist.id
         cls.contract = cls.env["contract.contract"].create(
             {
@@ -194,7 +201,7 @@ class TestSaleOrder(SavepointCase):
             {
                 "name": "Contract",
                 "contract_template_id": self.contract_template2.id,
-                "partner_id": self.sale.partner_id.id,
+                "partner_id": self.env.user.partner_id.id,
                 "line_recurrence": True,
             }
         )
@@ -218,6 +225,7 @@ class TestSaleOrder(SavepointCase):
     def test_no_contract_proudct(self):
         """it should create contract for only product contract"""
         self.product1.is_contract = False
+        self.order_line1.product_id_change()
         self.sale.action_confirm()
         self.assertFalse(self.order_line1.contract_id)
 
@@ -241,6 +249,7 @@ class TestSaleOrder(SavepointCase):
     def test_sale_order_create_invoice(self):
         """Should not invoice contract product on sale order create invoice"""
         self.product2.is_contract = False
+        self.order_line2.product_id_change()
         self.product2.invoice_policy = "order"
         self.order_line1._compute_auto_renew()
         self.sale.action_confirm()
diff --git a/product_contract/views/sale_order.xml b/product_contract/views/sale_order.xml
index a0ea683d0..2b08163fd 100644
--- a/product_contract/views/sale_order.xml
+++ b/product_contract/views/sale_order.xml
@@ -38,6 +38,7 @@
                 position="after"
             >
                 <field name="contract_template_id" attrs="{'invisible': []}" />
+                <field name="is_contract" invisible="1" />
                 <field
                     name="contract_id"
                     options='{"no_create": True}'