diff --git a/addons/mrp/wizard/change_production_qty.py b/addons/mrp/wizard/change_production_qty.py
index 1fe35abc201..9be34b6bd1e 100644
--- a/addons/mrp/wizard/change_production_qty.py
+++ b/addons/mrp/wizard/change_production_qty.py
@@ -68,7 +68,7 @@ class change_production_qty(osv.osv_memory):
         assert record_id, _('Active Id not found')
         prod_obj = self.pool.get('mrp.production')
         bom_obj = self.pool.get('mrp.bom')
-        move_lines_obj = self.pool.get('stock.move')
+        move_obj = self.pool.get('stock.move')
         for wiz_qty in self.browse(cr, uid, ids, context=context):
             prod = prod_obj.browse(cr, uid, record_id, context=context)
             prod_obj.write(cr, uid, [prod.id], {'product_qty': wiz_qty.product_qty})
@@ -88,17 +88,16 @@ class change_production_qty(osv.osv_memory):
                     raise osv.except_osv(_('Error!'), _("Cannot find bill of material for this product."))
 
                 factor = prod.product_qty * prod.product_uom.factor / bom_point.product_uom.factor
-                res = bom_obj._bom_explode(cr, uid, bom_point, factor / bom_point.product_qty, [])
-                pick_move = {}
-                for move_ln in prod.picking_id.move_lines:
-                    pick_move.update({move_ln.product_id.id: move_ln.id})
-                for r in res[0]:
+                product_details, workcenter_details = \
+                    bom_obj._bom_explode(cr, uid, bom_point, factor / bom_point.product_qty, [])
+                product_move = dict((mv.product_id.id, mv.id) for mv in prod.picking_id.move_lines)
+                for r in product_details:
                     if r['product_id'] == move.product_id.id:
-                        move_lines_obj.write(cr, uid, [move.id], {'product_qty' :  r['product_qty']})
-                    if r['product_id'] in pick_move:
-                        move_lines_obj.write(cr, uid, [pick_move[r['product_id']]], {'product_qty' :  r['product_qty']})
+                        move_obj.write(cr, uid, [move.id], {'product_qty': r['product_qty']})
+                    if r['product_id'] in product_move:
+                        move_obj.write(cr, uid, [product_move[r['product_id']]], {'product_qty': r['product_qty']})
             if prod.move_prod_id:
-                move_lines_obj.write(cr, uid, [prod.move_prod_id.id], {'product_qty' :  wiz_qty.product_qty})
+                move_obj.write(cr, uid, [prod.move_prod_id.id], {'product_qty' :  wiz_qty.product_qty})
             self._update_product_to_produce(cr, uid, prod, wiz_qty.product_qty, context=context)
         return {}