diff --git a/addons/stock/stock.py b/addons/stock/stock.py
index efd596684cb..bee8275a688 100644
--- a/addons/stock/stock.py
+++ b/addons/stock/stock.py
@@ -1927,7 +1927,8 @@ class stock_move(osv.osv):
             'product_uom': product.uom_id.id,
             'product_uos': uos_id,
             'product_qty': 1.00,
-            'product_uos_qty' : self.pool.get('stock.move').onchange_quantity(cr, uid, ids, prod_id, 1.00, product.uom_id.id, uos_id)['value']['product_uos_qty']
+            'product_uos_qty' : self.pool.get('stock.move').onchange_quantity(cr, uid, ids, prod_id, 1.00, product.uom_id.id, uos_id)['value']['product_uos_qty'],
+            'prodlot_id' : False,
         }
         if not ids:
             result['name'] = product.partner_ref
@@ -2896,11 +2897,11 @@ class stock_inventory_line(osv.osv):
         @return:  Dictionary of changed values
         """
         if not product:
-            return {'value': {'product_qty': 0.0, 'product_uom': False}}
+            return {'value': {'product_qty': 0.0, 'product_uom': False, 'prod_lot_id': False}}
         obj_product = self.pool.get('product.product').browse(cr, uid, product)
         uom = uom or obj_product.uom_id.id
         amount = self.pool.get('stock.location')._product_get(cr, uid, location_id, [product], {'uom': uom, 'to_date': to_date, 'compute_child': False})[product]
-        result = {'product_qty': amount, 'product_uom': uom}
+        result = {'product_qty': amount, 'product_uom': uom, 'prod_lot_id': False}
         return {'value': result}
 
 stock_inventory_line()