diff --git a/addons/account/invoice.py b/addons/account/invoice.py
index 269a4a0c0f4..21b4170388c 100644
--- a/addons/account/invoice.py
+++ b/addons/account/invoice.py
@@ -1609,7 +1609,11 @@ class res_partner(osv.osv):
     _columns = {
         'invoice_ids': fields.one2many('account.invoice.line', 'partner_id', 'Invoices', readonly=True),
     }
-
+    
+    def copy(self, cr, uid, id, default={}, context={}):
+        default.update({'invoice_ids' : False})
+        return super(res_partner, self).copy(cr, uid, id, default, context)
+    
 res_partner()
 
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