diff --git a/production.py b/production.py
index 401b025..6ad9ae6 100644
--- a/production.py
+++ b/production.py
@@ -22,8 +22,7 @@ def process_sale(func):
     return wrapper
 
 
-class Production:
-    __metaclass__ = PoolMeta
+class Production(metaclass=PoolMeta):
     __name__ = 'production'
 
     sale_exception_state = fields.Function(fields.Selection([
diff --git a/purchase_request.py b/purchase_request.py
index 57b308f..4efc090 100644
--- a/purchase_request.py
+++ b/purchase_request.py
@@ -10,8 +10,7 @@ from trytond.transaction import Transaction
 __all__ = ['PurchaseRequest']
 
 
-class PurchaseRequest:
-    __metaclass__ = PoolMeta
+class PurchaseRequest(metaclass=PoolMeta):
     __name__ = 'purchase.request'
 
     @classmethod
diff --git a/sale.py b/sale.py
index 904def0..bf75662 100644
--- a/sale.py
+++ b/sale.py
@@ -13,8 +13,7 @@ __all__ = ['Sale', 'SaleLine',
     'HandleProductionExceptionAsk', 'HandleProductionException']
 
 
-class Sale:
-    __metaclass__ = PoolMeta
+class Sale(metaclass=PoolMeta):
     __name__ = 'sale.sale'
 
     production_state = fields.Selection([
@@ -114,8 +113,7 @@ class Sale:
         return production_by_line
 
 
-class SaleLine:
-    __metaclass__ = PoolMeta
+class SaleLine(metaclass=PoolMeta):
     __name__ = 'sale.line'
 
     productions = fields.One2Many('production', 'origin', 'Productions',
diff --git a/setup.py b/setup.py
index 14489b7..10c3a37 100644
--- a/setup.py
+++ b/setup.py
@@ -4,7 +4,7 @@
 from setuptools import setup
 import re
 import os
-import ConfigParser
+import configparser
 
 MODULE = 'sale_product_raw'
 PREFIX = 'nantic'
@@ -14,7 +14,7 @@ MODULE2PREFIX = {}
 def read(fname):
     return open(os.path.join(os.path.dirname(__file__), fname)).read()
 
-config = ConfigParser.ConfigParser()
+config = configparser.ConfigParser()
 config.readfp(open('tryton.cfg'))
 info = dict(config.items('tryton'))
 for key in ('depends', 'extras_depend', 'xml'):
diff --git a/tests/scenario_sale_product_raw.rst b/tests/scenario_sale_product_raw.rst
index fdd5882..567d9c5 100644
--- a/tests/scenario_sale_product_raw.rst
+++ b/tests/scenario_sale_product_raw.rst
@@ -125,7 +125,7 @@ Sale services::
     >>> service_sale.click('confirm')
     >>> service_sale.click('process')
     >>> service_sale.state
-    u'processing'
+    'processing'
     >>> service_invoice, = service_sale.invoices
     >>> service_sale.productions == []
     True
@@ -146,13 +146,13 @@ Sale 5 products::
     >>> sale.click('confirm')
     >>> sale.click('process')
     >>> sale.state
-    u'processing'
+    'processing'
     >>> sale.reload()
     >>> len(sale.shipments), len(sale.shipment_returns), len(sale.productions)
     (1, 0, 1)
     >>> production, = sale.productions
     >>> production.state
-    u'draft'
+    'draft'
     >>> input, = production.inputs
     >>> input.product == raw_product
     True