diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index e276ce0c48f..4ddc2bc9eb8 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -557,6 +557,7 @@ class purchase_order(osv.osv):
 
     def invoice_done(self, cr, uid, ids, context=None):
         self.write(cr, uid, ids, {'state':'approved'}, context=context)
+        self.message_post(cr, uid, ids, body=_("Invoice <b>Paid.</b>"), context=context)
         return True
 
     def has_stockable_product(self, cr, uid, ids, *args):