diff --git a/addons/sale_timesheet/models/account.py b/addons/sale_timesheet/models/account.py
index 07c70419b89..55683a33745 100644
--- a/addons/sale_timesheet/models/account.py
+++ b/addons/sale_timesheet/models/account.py
@@ -26,8 +26,8 @@ class AccountAnalyticLine(models.Model):
 
     @api.multi
     def write(self, values):
-        # prevent to update invoiced timesheets if product_id is not of type order
-        if self.so_line.product_id.invoice_policy != "order" and self.filtered(lambda timesheet: timesheet.timesheet_invoice_id):
+        # prevent to update invoiced timesheets if one line is of type delivery
+        if self.filtered(lambda aal: aal.so_line.product_id.invoice_policy == "delivery") and self.filtered(lambda timesheet: timesheet.timesheet_invoice_id):
             if any([field_name in values for field_name in ['unit_amount', 'employee_id', 'task_id', 'timesheet_revenue', 'so_line', 'amount', 'date']]):
                 raise UserError(_('You can not modify already invoiced timesheets.'))
 
diff --git a/addons/sale_timesheet/tests/test_timesheet_revenue.py b/addons/sale_timesheet/tests/test_timesheet_revenue.py
index 1fa0b40fcd2..6f1533d3ca1 100644
--- a/addons/sale_timesheet/tests/test_timesheet_revenue.py
+++ b/addons/sale_timesheet/tests/test_timesheet_revenue.py
@@ -186,15 +186,20 @@ class TestSaleTimesheet(TestSale):
         self.assertEquals(timesheet2.timesheet_invoice_id, invoice)
         self.assertEquals(timesheet3.timesheet_invoice_id, invoice)
 
-        # check that analytic line for product 'ordered' can be altered
+        # check that analytic line for product 'delivery' cannot be altered
         with self.assertRaises(UserError):
             timesheet1.write(dict(unit_amount=10))
         self.assertNotEquals(timesheet1.unit_amount, 10)
 
-        # check that analytic line for product 'delivered' cannot be altered
+        # check that analytic line for product 'ordered' can be altered
         timesheet3.write(dict(unit_amount=10))
         self.assertEquals(timesheet3.unit_amount, 10)
 
+        # check that if at least 1 analytic line is for product 'delivery', it cannot be altered
+        with self.assertRaises(UserError):
+            (timesheet1 + timesheet3).write(dict(unit_amount=15))
+        self.assertNotEquals(timesheet1.unit_amount, 15)
+        self.assertNotEquals(timesheet3.unit_amount, 15)
 
     def test_revenue_multi_currency(self):
         """ Create a SO with 2 lines : one for a delivered service, one for a ordered service. Confirm