diff --git a/addons/account_voucher/account_voucher.py b/addons/account_voucher/account_voucher.py
index 7e7cd9d6507..f6ce6e0823a 100644
--- a/addons/account_voucher/account_voucher.py
+++ b/addons/account_voucher/account_voucher.py
@@ -226,7 +226,7 @@ class account_voucher(osv.osv):
         if context.get('type', 'sale') in ('purchase', 'payment'):
             nodes = doc.xpath("//field[@name='partner_id']")
             for node in nodes:
-                node.set('context', "{'search_default_supplier': 1}")
+                node.set('context', "{'default_customer': 0, 'search_default_supplier': 1, 'default_supplier': 1}")
                 if context.get('invoice_type','') in ('in_invoice', 'in_refund'):
                     node.set('string', _("Supplier"))
         res['arch'] = etree.tostring(doc)