diff --git a/addons/stock/product.py b/addons/stock/product.py
index 27b7590cf5d..2a819ea89b2 100644
--- a/addons/stock/product.py
+++ b/addons/stock/product.py
@@ -248,6 +248,7 @@ class product_product(osv.osv):
             date_str = "date<=%s"
             date_values = [to_date]
 
+        prodlot_id = context.get('prodlot_id', False)
 
     # TODO: perhaps merge in one query.
         if date_values:
@@ -257,10 +258,11 @@ class product_product(osv.osv):
             cr.execute(
                 'select sum(product_qty), product_id, product_uom '\
                 'from stock_move '\
-                'where location_id NOT IN %s'\
-                'and location_dest_id IN %s'\
-                'and product_id IN %s'\
-                'and state IN %s' + (date_str and 'and '+date_str+' ' or '') +''\
+                'where location_id NOT IN %s '\
+                'and location_dest_id IN %s '\
+                'and product_id IN %s '\
+                '' + (prodlot_id and ('and prodlot_id = ' + str(prodlot_id)) or '') + ' '\
+                'and state IN %s ' + (date_str and 'and '+date_str+' ' or '') +' '\
                 'group by product_id,product_uom',tuple(where))
             results = cr.fetchall()
         if 'out' in what:
@@ -268,10 +270,11 @@ class product_product(osv.osv):
             cr.execute(
                 'select sum(product_qty), product_id, product_uom '\
                 'from stock_move '\
-                'where location_id IN %s'\
+                'where location_id IN %s '\
                 'and location_dest_id NOT IN %s '\
-                'and product_id  IN %s'\
-                'and state in %s' + (date_str and 'and '+date_str+' ' or '') + ''\
+                'and product_id  IN %s '\
+                '' + (prodlot_id and ('and prodlot_id = ' + str(prodlot_id)) or '') + ' '\
+                'and state in %s ' + (date_str and 'and '+date_str+' ' or '') + ' '\
                 'group by product_id,product_uom',tuple(where))
             results2 = cr.fetchall()
         uom_obj = self.pool.get('product.uom')
diff --git a/addons/stock/stock.py b/addons/stock/stock.py
index af1b783709e..aeb82269357 100644
--- a/addons/stock/stock.py
+++ b/addons/stock/stock.py
@@ -2556,7 +2556,7 @@ class stock_inventory(osv.osv):
             move_ids = []
             for line in inv.inventory_line_id:
                 pid = line.product_id.id
-                product_context.update(uom=line.product_uom.id,date=inv.date)
+                product_context.update(uom=line.product_uom.id, date=inv.date, prodlot_id=line.prod_lot_id.id)
                 amount = location_obj._product_get(cr, uid, line.location_id.id, [pid], product_context)[pid]
 
                 change = line.product_qty - amount