diff --git a/CHANGELOG.md b/CHANGELOG.md
index 400399f..537460e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 - Test the project against both `unidecode` and `text_unidecode`.
 - Fix type annotation issues identified by mypy.
 - Run CI against pull requests.
+- Fix package build warnings.
 
 ## 8.0.4
 
diff --git a/pyproject.toml b/pyproject.toml
index de62727..1c02bfe 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,8 @@
+[build-system]
+requires = ["setuptools>=61.2"]
+build-backend = "setuptools.build_meta"
+
+
 # coverage
 # --------
 
diff --git a/setup.py b/setup.py
index 1d0e2d5..32f44dd 100755
--- a/setup.py
+++ b/setup.py
@@ -3,7 +3,6 @@
 import os
 import sys
 
-from codecs import open
 from shutil import rmtree
 from setuptools import setup
 
@@ -14,13 +13,12 @@
 
 install_requires = ['text-unidecode>=1.3']
 extras_requires = {'unidecode': ['Unidecode>=1.1.1']}
-test_requires = []
 
 about = {}
-with open(os.path.join(here, package, '__version__.py'), 'r', 'utf-8') as f:
+with open(os.path.join(here, package, '__version__.py'), 'r', encoding='utf-8') as f:
     exec(f.read(), about)
 
-with open('README.md', 'r', 'utf-8') as f:
+with open('README.md', 'r', encoding='utf-8') as f:
     readme = f.read()
 
 
@@ -66,7 +64,6 @@ def status(s):
     include_package_data=True,
     python_requires=python_requires,
     install_requires=install_requires,
-    tests_require=test_requires,
     extras_require=extras_requires,
     zip_safe=False,
     cmdclass={},
@@ -75,7 +72,6 @@ def status(s):
         'Development Status :: 5 - Production/Stable',
         'Intended Audience :: Developers',
         'Natural Language :: English',
-        'License :: OSI Approved :: MIT License',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.10',
diff --git a/slugify/__version__.py b/slugify/__version__.py
index 854038e..a9cd778 100644
--- a/slugify/__version__.py
+++ b/slugify/__version__.py
@@ -3,6 +3,6 @@
 __author_email__ = 'info@neekware.com'
 __description__ = 'A Python slugify application that also handles Unicode'
 __url__ = 'https://github.com/un33k/python-slugify'
-__license__ = 'MIT'
+__license__ = 'SPDX-License-Identifier: MIT'
 __copyright__ = 'Copyright 2022 Val Neekman @ Neekware Inc.'
 __version__ = '8.0.4'