diff --git a/.drone.yml b/.drone.yml
index 67aa49b..82ae06b 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -32,15 +32,15 @@ services:
 
 matrix:
     include:
-        - IMAGE: python:2.7
-          TOXENV: py27
-          DATABASE: sqlite
-        - IMAGE: python:2.7
-          TOXENV: py27
-          DATABASE: postgresql
         - IMAGE: python:3.6
           TOXENV: py36
           DATABASE: sqlite
         - IMAGE: python:3.6
           TOXENV: py36
           DATABASE: postgresql
+        - IMAGE: python:3.7
+          TOXENV: py37
+          DATABASE: sqlite
+        - IMAGE: python:3.7
+          TOXENV: py37
+          DATABASE: postgresql
\ No newline at end of file
diff --git a/INSTALL b/INSTALL
index b01e1e4..91d1620 100644
--- a/INSTALL
+++ b/INSTALL
@@ -4,7 +4,6 @@ Installing datalife_stock_lot_cost_price
 Prerequisites
 -------------
 
- * Python 2.7 or later (http://www.python.org/)
  * trytond (http://www.tryton.org/)
 
 Installation
diff --git a/setup.py b/setup.py
index 232f8d1..a033a68 100644
--- a/setup.py
+++ b/setup.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # The COPYRIGHT file at the top level of this repository contains
 # the full copyright notices and license terms.
 
@@ -6,10 +6,7 @@ from setuptools import setup, find_packages
 import re
 import os
 import io
-try:
-    from configparser import ConfigParser
-except ImportError:
-    from ConfigParser import ConfigParser
+from configparser import ConfigParser
 
 MODULE2PREFIX = {}
 
@@ -19,6 +16,7 @@ def read(fname):
         os.path.join(os.path.dirname(__file__), fname),
         'r', encoding='utf-8').read()
 
+
 def get_require_version(name):
     if minor_version % 2:
         require = '%s >= %s.%s.dev0, < %s.%s'
@@ -28,6 +26,7 @@ def get_require_version(name):
         major_version, minor_version + 1)
     return require
 
+
 config = ConfigParser()
 config.readfp(open('tryton.cfg'))
 info = dict(config.items('tryton'))
@@ -45,9 +44,12 @@ requires = []
 for dep in info.get('depends', []):
     if not re.match(r'(ir|res)(\W|$)', dep):
         prefix = MODULE2PREFIX.get(dep, 'trytond')
+
         requires.append(get_require_version('%s_%s' % (prefix, dep)))
+
 requires.append(get_require_version('trytond'))
 
+
 tests_require = [get_require_version('proteus')]
 series = '%s.%s' % (major_version, minor_version)
 if minor_version % 2:
@@ -99,15 +101,16 @@ setup(name=name,
         'Natural Language :: Slovenian',
         'Natural Language :: Spanish',
         'Operating System :: OS Independent',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: Implementation :: CPython',
         'Programming Language :: Python :: Implementation :: PyPy',
         'Topic :: Office/Business',
         ],
     license='GPL-3',
+    python_requires='>=3.4',
     install_requires=requires,
     dependency_links=dependency_links,
     zip_safe=False,
@@ -118,8 +121,4 @@ setup(name=name,
     test_suite='tests',
     test_loader='trytond.test_loader:Loader',
     tests_require=tests_require,
-    use_2to3=True,
-    convert_2to3_doctests=[
-            'tests/scenario_stock_lot_cost_price.rst',
-        ],
     )
diff --git a/stock.py b/stock.py
index ab88f64..dd97307 100644
--- a/stock.py
+++ b/stock.py
@@ -8,9 +8,8 @@ from trytond.transaction import Transaction
 __all__ = ['Lot']
 
 
-class Lot:
+class Lot(metaclass=PoolMeta):
     __name__ = 'stock.lot'
-    __metaclass__ = PoolMeta
 
     cost_price = fields.Function(fields.Numeric(
         'Cost Price', digits=price_digits), 'get_cost_price')
diff --git a/tests/scenario_stock_lot_cost_price.rst b/tests/scenario_stock_lot_cost_price.rst
index ba79b59..04ce2b6 100644
--- a/tests/scenario_stock_lot_cost_price.rst
+++ b/tests/scenario_stock_lot_cost_price.rst
@@ -54,6 +54,16 @@ Create parties::
     >>> customer = Party(name='Customer')
     >>> customer.save()
 
+Create account category::
+
+    >>> ProductCategory = Model.get('product.category')
+    >>> account_category = ProductCategory(name="Account Category")
+    >>> account_category.accounting = True
+    >>> account_category.account_expense = expense
+    >>> account_category.account_revenue = revenue
+    >>> account_category.supplier_taxes.append(tax)
+    >>> account_category.save()
+
 Create product::
 
     >>> ProductUom = Model.get('product.uom')
@@ -68,9 +78,7 @@ Create product::
     >>> template.salable = True
     >>> template.list_price = Decimal('10')
     >>> template.cost_price_method = 'fixed'
-    >>> template.account_expense = expense
-    >>> template.account_revenue = revenue
-    >>> template.supplier_taxes.append(tax)
+    >>> template.account_category = account_category
     >>> product, = template.products
     >>> product.cost_price = Decimal('5')
     >>> template.save()
diff --git a/tox.ini b/tox.ini
index f8a2206..718b574 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,18 +1,15 @@
 [tox]
-envlist = {py27,py36}-{sqlite,postgresql,mysql},pypy-{sqlite,postgresql}
+envlist = {py36,py37}-{sqlite,postgresql},pypy3-{sqlite,postgresql}
 
 [testenv]
 commands = {envpython} setup.py test
 deps =
-    {py27,py36}-postgresql: psycopg2 >= 2.5
-    pypy-postgresql: psycopg2cffi >= 2.5
-    mysql: MySQL-python
-    sqlite: sqlitebck
+    {py36,py37}-postgresql: psycopg2 >= 2.5
+    pypy3-postgresql: psycopg2cffi >= 2.5
+    {py36}-sqlite: sqlitebck
 setenv =
     sqlite: TRYTOND_DATABASE_URI={env:SQLITE_URI:sqlite://}
     postgresql: TRYTOND_DATABASE_URI={env:POSTGRESQL_URI:postgresql://}
-    mysql: TRYTOND_DATABASE_URI={env:MYSQL_URI:mysql://}
     sqlite: DB_NAME={env:SQLITE_NAME::memory:}
     postgresql: DB_NAME={env:POSTGRESQL_NAME:test}
-    mysql: DB_NAME={env:MYSQL_NAME:test}
-install_command = pip install --pre {opts} {packages}
+install_command = pip install --pre --find-links https://trydevpi.tryton.org/ {opts} {packages}
\ No newline at end of file
diff --git a/tryton.cfg b/tryton.cfg
index b253eb7..7f9cf0e 100644
--- a/tryton.cfg
+++ b/tryton.cfg
@@ -1,5 +1,5 @@
 [tryton]
-version=4.8.0
+version=5.0.0
 depends:
     ir
     res