diff --git a/addons/crm/wizard/crm_lead_to_opportunity.py b/addons/crm/wizard/crm_lead_to_opportunity.py
index 9e1109e0440..0b73ce472ae 100644
--- a/addons/crm/wizard/crm_lead_to_opportunity.py
+++ b/addons/crm/wizard/crm_lead_to_opportunity.py
@@ -37,6 +37,9 @@ class crm_lead2opportunity_partner(osv.osv_memory):
         'opportunity_ids': fields.many2many('crm.lead', string='Opportunities'),
     }
 
+    def onchange_action(self, cr, uid, ids, action, context=None):
+        return {'value': {'partner_id': False if action != 'exist' else self._find_matching_partner(cr, uid, context=context)}}
+
     def default_get(self, cr, uid, fields, context=None):
         """
         Default get for name, opportunity_ids.
diff --git a/addons/crm/wizard/crm_lead_to_opportunity_view.xml b/addons/crm/wizard/crm_lead_to_opportunity_view.xml
index 00686de1c8e..9f7701a1752 100644
--- a/addons/crm/wizard/crm_lead_to_opportunity_view.xml
+++ b/addons/crm/wizard/crm_lead_to_opportunity_view.xml
@@ -27,7 +27,7 @@
                         </field>
                     </group>
                     <group name="action" attrs="{'invisible': [('name', '!=', 'convert')]}">
-                        <field name="action" class="oe_inline"/>
+                        <field name="action" on_change="onchange_action(action, context)" class="oe_inline"/>
                         <field name="partner_id"
                             attrs="{'required': [('action', '=', 'exist')], 'invisible':[('action','!=','exist')]}"
                             class="oe_inline"/>