diff --git a/addons/stock_account/stock.py b/addons/stock_account/stock.py
index 1e8555b0cc7..e4355a0e7fa 100644
--- a/addons/stock_account/stock.py
+++ b/addons/stock_account/stock.py
@@ -273,8 +273,12 @@ class stock_picking(osv.osv):
         else:
             account_id = partner.property_account_payable_id.id
             payment_term = partner.property_supplier_payment_term_id.id or False
+        if not move.origin:
+            origin = move.picking_id.name
+        else:
+            origin = move.picking_id.name + ', ' + move.origin
         return {
-            'origin': move.picking_id.name,
+            'origin': origin,
             'date_invoice': context.get('date_inv', False),
             'user_id': user_id,
             'partner_id': partner.id,
@@ -304,7 +308,6 @@ class stock_picking(osv.osv):
 
             key = (partner, currency_id, company.id, _user_id)
             invoice_vals = self._get_invoice_vals(cr, uid, key, inv_type, journal_id, move, context=context)
-
             if key not in invoices:
                 # Get account and payment terms
                 invoice_id = self._create_invoice_from_picking(cr, uid, move.picking_id, invoice_vals, context=context)
@@ -312,8 +315,9 @@ class stock_picking(osv.osv):
             else:
                 invoice = invoice_obj.browse(cr, uid, invoices[key], context=context)
                 if not invoice.origin or invoice_vals['origin'] not in invoice.origin.split(', '):
-                    invoice_origin = filter(None, [invoice.origin, invoice_vals['origin']])
-                    invoice.write({'origin': ', '.join(invoice_origin)})
+                    elements = (invoice.origin or '').split(',') + (invoice_vals['origin'] or '').split(',')
+                    invoice_origin = ', '.join(set(e.strip() for e in elements))
+                    invoice.write({'origin': invoice_origin})
 
             invoice_line_vals = move_obj._get_invoice_line_vals(cr, uid, move, partner, inv_type, context=context)
             invoice_line_vals['invoice_id'] = invoices[key]