diff --git a/addons/account_voucher/account_voucher.py b/addons/account_voucher/account_voucher.py
index 061a213d8d0..cf2c25e3e5f 100644
--- a/addons/account_voucher/account_voucher.py
+++ b/addons/account_voucher/account_voucher.py
@@ -1557,6 +1557,14 @@ account_bank_statement()
 class account_bank_statement_line(osv.osv):
     _inherit = 'account.bank.statement.line'
 
+    def onchange_partner_id(self, cr, uid, ids, partner_id, context=None):
+        res = super(account_bank_statement_line, self).onchange_partner_id(cr, uid, ids, partner_id, context=context)
+        res['value'].update({'voucher_id' : False})
+        return res
+
+    def onchange_amount(self, cr, uid, ids, amount, context=None):
+        return {'value' :  {'voucher_id' : False}}
+
     def _amount_reconciled(self, cursor, user, ids, name, args, context=None):
         if not ids:
             return {}
diff --git a/addons/account_voucher/account_voucher_view.xml b/addons/account_voucher/account_voucher_view.xml
index 0bed5793587..7460feada15 100644
--- a/addons/account_voucher/account_voucher_view.xml
+++ b/addons/account_voucher/account_voucher_view.xml
@@ -225,6 +225,9 @@
                 <xpath expr="//page[@name='statement_line_ids']/field[@name='line_ids']/form/group/field[@name='sequence']" position="before">
                     <field name="voucher_id" widget="many2onebutton" context="{'line_type': type, 'default_type': amount &lt; 0 and 'payment' or 'receipt', 'type': amount &lt; 0 and 'payment' or 'receipt', 'default_partner_id': partner_id, 'default_journal_id': parent.journal_id, 'default_amount': abs(amount), 'default_reference': ref, 'default_date': date, 'default_name': name}"/>
                 </xpath>
+                <field name="amount" position="attributes">
+                    <attribute name="on_change">onchange_amount(amount)</attribute>
+                </field>
             </field>
         </record>