diff --git a/addons/account/account_invoice_view.xml b/addons/account/account_invoice_view.xml
index 02924dad580..48624253bc6 100644
--- a/addons/account/account_invoice_view.xml
+++ b/addons/account/account_invoice_view.xml
@@ -156,7 +156,7 @@
                         <field name="currency_id" on_change="onchange_currency_id(currency_id, company_id)" width="50"/>
                         <button name="%(action_account_change_currency)d" type="action" icon="terp-stock_effects-object-colorize" string="Change" attrs="{'invisible':[('state','!=','draft')]}" groups="account.group_account_user"/>
                         <newline/>
-                        <field name="partner_id" domain="[('supplier','=', 1)]" on_change="onchange_partner_id(type,partner_id,date_invoice,payment_term, partner_bank_id,company_id)" context="{'default_customer': 0}"/>
+                        <field string="Vendor" name="partner_id" domain="[('supplier','=', 1)]" on_change="onchange_partner_id(type,partner_id,date_invoice,payment_term, partner_bank_id,company_id)" context="{'default_customer': 0}"/>
                         <field domain="[('partner_id','=',partner_id)]" name="address_invoice_id"/>
                         <field name="fiscal_position" groups="base.group_extended" widget="selection"/>
                         <newline/>
@@ -265,7 +265,7 @@
                     <field name="currency_id" on_change="onchange_currency_id(currency_id, company_id)" width="50"/>
                     <button name="%(action_account_change_currency)d" type="action" icon="terp-stock_effects-object-colorize" string="Change" attrs="{'invisible':[('state','!=','draft')]}" groups="account.group_account_user"/>
                     <newline/>
-                    <field name="partner_id" on_change="onchange_partner_id(type,partner_id,date_invoice,payment_term, partner_bank_id,company_id)" groups="base.group_user"/>
+                    <field string="Customer" name="partner_id" on_change="onchange_partner_id(type,partner_id,date_invoice,payment_term, partner_bank_id,company_id)" groups="base.group_user"/>
                     <field domain="[('partner_id','=',partner_id)]" name="address_invoice_id"/>
                     <field name="fiscal_position" groups="base.group_extended" widget="selection"/>
                     <newline/>
diff --git a/addons/account/invoice.py b/addons/account/invoice.py
index 870b3b853bb..79978c0bbaf 100644
--- a/addons/account/invoice.py
+++ b/addons/account/invoice.py
@@ -20,6 +20,7 @@
 ##############################################################################
 
 import time
+from lxml import etree
 import decimal_precision as dp
 
 import netsvc
@@ -346,6 +347,16 @@ class account_invoice(osv.osv):
             if field == 'journal_id':
                 journal_select = journal_obj._name_search(cr, uid, '', [('type', '=', type)], context=context, limit=None, name_get_uid=1)
                 res['fields'][field]['selection'] = journal_select
+
+        if view_type == 'tree':
+            doc = etree.XML(res['arch'])
+            nodes = doc.xpath("//field[@name='partner_id']")
+            partner_string = 'Customer'
+            if context.get('type', 'out_invoice') in ('in_invoice', 'in_refund'):
+                partner_string = 'Vendor'
+            for node in nodes:
+                node.set('string', partner_string)
+            res['arch'] = etree.tostring(doc)
         return res
 
     def create(self, cr, uid, vals, context=None):