diff --git a/__init__.py b/__init__.py
index dcd514b..e1f10be 100644
--- a/__init__.py
+++ b/__init__.py
@@ -2,11 +2,10 @@
 # The COPYRIGHT file at the top level of this repository contains
 # the full copyright notices and license terms.
 from trytond.pool import Pool
-from .stock import *
+from . import stock
 
 
 def register():
     Pool.register(
-        Lot,
+        stock.Lot,
         module='stock_lot_date', type_='model')
-
diff --git a/setup.py b/setup.py
index c5c0d19..a63cc07 100644
--- a/setup.py
+++ b/setup.py
@@ -7,10 +7,7 @@ from setuptools import setup
 import re
 import os
 import io
-try:
-    from configparser import ConfigParser
-except ImportError:
-    from ConfigParser import ConfigParser
+from configparser import ConfigParser
 
 MODULE2PREFIX = {}
 
diff --git a/stock.py b/stock.py
index 390d3f4..ed250d2 100644
--- a/stock.py
+++ b/stock.py
@@ -7,8 +7,7 @@ from trytond.pool import Pool, PoolMeta
 __all__ = ['Lot']
 
 
-class Lot:
-    __metaclass__ = PoolMeta
+class Lot(metaclass=PoolMeta):
     __name__ = 'stock.lot'
     lot_date = fields.Date('Date Lot', required=True)
 
diff --git a/tryton.cfg b/tryton.cfg
index 85c5d6a..0bb141a 100644
--- a/tryton.cfg
+++ b/tryton.cfg
@@ -1,5 +1,5 @@
 [tryton]
-version=4.8.0
+version=4.9.0
 depends:
     ir
     res