diff --git a/contract_payment_mode/models/contract.py b/contract_payment_mode/models/contract.py
index 8041d6b4d..d5c6f6ef9 100644
--- a/contract_payment_mode/models/contract.py
+++ b/contract_payment_mode/models/contract.py
@@ -13,7 +13,11 @@ class ContractContract(models.Model):
 
     @api.onchange("partner_id")
     def on_change_partner_id(self):
-        self.payment_mode_id = self.partner_id.customer_payment_mode_id.id
+        partner = self.with_company(self.company_id).partner_id
+        if self.contract_type == "purchase":
+            self.payment_mode_id = partner.supplier_payment_mode_id.id
+        else:
+            self.payment_mode_id = partner.customer_payment_mode_id.id
 
     def _prepare_invoice(self, date_invoice, journal=None):
         invoice_vals, move_form = super()._prepare_invoice(