diff --git a/addons/stock/stock.py b/addons/stock/stock.py
index 31d5a68c9fe..14ee58bafd7 100644
--- a/addons/stock/stock.py
+++ b/addons/stock/stock.py
@@ -2923,6 +2923,11 @@ class stock_picking_out(osv.osv):
         #instead of it's own workflow (which is not existing)
         return self.pool.get('stock.picking')._workflow_trigger(cr, uid, ids, trigger, context=context)
 
+    def _workflow_signal(self, cr, uid, ids, signal, context=None):
+        #override in order to Fire the workflow Signal on given stock.picking workflow instance.
+        #instead of it's own workflow (which is not existing)
+        return self.pool.get('stock.picking')._workflow_signal(cr, uid, ids, signal, context=context)
+
     _columns = {
         'state': fields.selection(
             [('draft', 'Draft'),