diff --git a/partner_contact_in_several_companies/models/res_partner.py b/partner_contact_in_several_companies/models/res_partner.py
index 8770cf0e8f45..8de77f167851 100644
--- a/partner_contact_in_several_companies/models/res_partner.py
+++ b/partner_contact_in_several_companies/models/res_partner.py
@@ -94,16 +94,14 @@ def unlink(self):
         return super(ResPartner, modified_self).unlink()
 
     @api.multi
-    def _commercial_partner_compute(self, name, args):
+    def _compute_commercial_partner(self):
         """ Returns the partner that is considered the commercial
         entity of this partner. The commercial entity holds the master data
         for all commercial fields (see :py:meth:`~_commercial_fields`) """
-        result = super(ResPartner, self)._commercial_partner_compute(name,
-                                                                     args)
+        result = super(ResPartner, self)._compute_commercial_partner()
         for partner in self:
             if partner.contact_type == 'attached' and not partner.parent_id:
-                result[partner.id] = partner.contact_id.id
-        return result
+                partner.commercial_partner_id = partner.contact_id
 
     def _contact_fields(self):
         """ Returns the list of contact fields that are synced from the parent
diff --git a/partner_contact_in_several_companies/tests/test_partner_contact_in_several_companies.py b/partner_contact_in_several_companies/tests/test_partner_contact_in_several_companies.py
index e016c9744343..39b4ab887343 100644
--- a/partner_contact_in_several_companies/tests/test_partner_contact_in_several_companies.py
+++ b/partner_contact_in_several_companies/tests/test_partner_contact_in_several_companies.py
@@ -231,6 +231,13 @@ def test_07_contact_onchange(self):
             'Bob Egnops',
         )
 
+        new_contact.write({'parent_id': False})
+        new_contact._compute_commercial_partner()
+        self.assertEqual(
+            new_contact.contact_id,
+            new_contact.commercial_partner_id,
+        )
+
         new_contact.write({'contact_type': 'standalone'})
         new_contact._onchange_contact_type()