diff --git a/odoo/addons/base/wizard/base_partner_merge.py b/odoo/addons/base/wizard/base_partner_merge.py
index 394144a72be..fe9dd800bb3 100644
--- a/odoo/addons/base/wizard/base_partner_merge.py
+++ b/odoo/addons/base/wizard/base_partner_merge.py
@@ -311,9 +311,10 @@ class MergePartnerAutomatic(models.TransientModel):
 
         # Make the company of all related users consistent with destination partner company
         if dst_partner.company_id:
-            for user in partner_ids.mapped('user_ids'):
-                user.sudo().write({'company_ids': [(6, 0, [dst_partner.company_id.id])],
-                            'company_id': dst_partner.company_id.id})
+            partner_ids.mapped('user_ids').sudo().write({
+                'company_ids': [(4, dst_partner.company_id.id)],
+                'company_id': dst_partner.company_id.id
+            })
 
         # call sub methods to do the merge
         self._update_foreign_keys(src_partners, dst_partner)