diff --git a/account_invoice_margin/models/account_invoice.py b/account_invoice_margin/models/account_invoice.py
index affb4596..dcebe9f2 100644
--- a/account_invoice_margin/models/account_invoice.py
+++ b/account_invoice_margin/models/account_invoice.py
@@ -1,5 +1,4 @@
 from odoo import api, fields, models
-from odoo.addons import decimal_precision as dp
 
 
 class AccountMoveLine(models.Model):
@@ -26,13 +25,15 @@ class AccountMoveLine(models.Model):
     def product_id_change_margin(self):
         for line in self:
             if not line.product_id:
-                return
-            line.purchase_price = line._compute_margin(line.move_id, line.product_id, line.product_uom_id, line.sale_line_ids)
+                line.purchase_price = 0
+            else:
+                line.purchase_price = line._compute_margin(line.move_id, line.product_id, line.product_uom_id, line.sale_line_ids)
 
     @api.model_create_multi
     def create(self, vals):
         line = super(AccountMoveLine, self).create(vals)
-        line.product_id_change_margin()
+        if 'purchase_price' not in vals[0]:
+            line.product_id_change_margin()
         return line
 
     @api.depends('product_id', 'purchase_price', 'quantity', 'price_unit', 'price_subtotal')
diff --git a/account_invoice_margin/tests/test_invoice_margin.py b/account_invoice_margin/tests/test_invoice_margin.py
index d62373d4..156c14c2 100644
--- a/account_invoice_margin/tests/test_invoice_margin.py
+++ b/account_invoice_margin/tests/test_invoice_margin.py
@@ -47,7 +47,7 @@ class TestInvoiceMargin(TestSaleMargin):
 
         account = self.env['account.account'].search([('internal_type', '=', 'other')], limit=1)
         inv = self.AccountMove.create({
-            'type': 'in_invoice',
+            'move_type': 'in_invoice',
             'partner_id': self.partner_id,
             'invoice_line_ids': [
                 (0, 0, {