diff --git a/.isort.cfg b/.isort.cfg
new file mode 100644
index 0000000000..e1c6495da9
--- /dev/null
+++ b/.isort.cfg
@@ -0,0 +1,3 @@
+[settings]
+multi_line_output=4
+known_first_party=trytond
diff --git a/__init__.py b/__init__.py
index fb26d729a4..c21bd525e2 100644
--- a/__init__.py
+++ b/__init__.py
@@ -2,6 +2,7 @@
 # this repository contains the full copyright notices and license terms.
 
 from trytond.pool import Pool
+
 from . import purchase
 
 __all__ = ['register']
diff --git a/purchase.py b/purchase.py
index 7f01c9fe28..19065fd59b 100644
--- a/purchase.py
+++ b/purchase.py
@@ -3,10 +3,9 @@
 
 from trytond.i18n import gettext
 from trytond.model import ModelSQL, ModelView, Workflow, fields
-from trytond.pool import Pool, PoolMeta
-from trytond.pyson import Eval, If, Bool
-
 from trytond.modules.product import price_digits
+from trytond.pool import Pool, PoolMeta
+from trytond.pyson import Bool, Eval, If
 
 from .exceptions import AmendmentValidateError
 
diff --git a/setup.py b/setup.py
index 3cfac42433..03ce6c1031 100755
--- a/setup.py
+++ b/setup.py
@@ -6,7 +6,8 @@ import io
 import os
 import re
 from configparser import ConfigParser
-from setuptools import setup, find_packages
+
+from setuptools import find_packages, setup
 
 
 def read(fname):
diff --git a/tests/__init__.py b/tests/__init__.py
index bd286fb671..8866a161d3 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -2,7 +2,8 @@
 # this repository contains the full copyright notices and license terms.
 
 try:
-    from trytond.modules.purchase_amendment.tests.test_purchase_amendment import suite  # noqa: E501
+    from trytond.modules.purchase_amendment.tests.test_purchase_amendment import \
+        suite  # noqa: E501
 except ImportError:
     from .test_purchase_amendment import suite
 
diff --git a/tests/test_purchase_amendment.py b/tests/test_purchase_amendment.py
index 11ad72d837..d509704338 100644
--- a/tests/test_purchase_amendment.py
+++ b/tests/test_purchase_amendment.py
@@ -1,14 +1,12 @@
 # This file is part of Tryton.  The COPYRIGHT file at the top level of
 # this repository contains the full copyright notices and license terms.
 
+import doctest
 import unittest
 
-import doctest
-
-from trytond.tests.test_tryton import ModuleTestCase
+from trytond.tests.test_tryton import (
+    ModuleTestCase, doctest_checker, doctest_teardown)
 from trytond.tests.test_tryton import suite as test_suite
-from trytond.tests.test_tryton import doctest_teardown
-from trytond.tests.test_tryton import doctest_checker
 
 
 class PurchaseAmendmentTestCase(ModuleTestCase):