diff --git a/django_ratelimit/__init__.py b/django_ratelimit/__init__.py
index 2a2e71e..8069e33 100644
--- a/django_ratelimit/__init__.py
+++ b/django_ratelimit/__init__.py
@@ -1,4 +1,4 @@
-VERSION = (3, 0, 1)
+VERSION = (4, 0, 0)
 __version__ = '.'.join(map(str, VERSION))
 
 ALL = (None,)  # Sentinel value for all HTTP methods.
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..2a15259
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,38 @@
+[build-system]
+requires = ["setuptools>=61.2"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "django-ratelimit"
+version = "4.0.0"
+authors = [{name = "James Socol", email = "me@jamessocol.com"}]
+requires-python = ">= 3.7"
+license = {file = "LICENSE"}
+description = "Cache-based rate-limiting for Django."
+readme = "README.rst"
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Environment :: Web Environment",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: Apache Software License",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.7",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Framework :: Django",
+    "Topic :: Software Development :: Libraries :: Python Modules",
+]
+urls = {Homepage = "https://github.com/jsocol/pystatsd"}
+
+[tool.distutils.bdist_wheel]
+universal = 1
+
+[tool.setuptools]
+include-package-data = true
+
+[tool.setuptools.packages]
+find = {namespaces = false}
diff --git a/run.sh b/run.sh
index cb54e0e..7850414 100755
--- a/run.sh
+++ b/run.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 export PYTHONPATH=".:$PYTHONPATH"
 export DJANGO_SETTINGS_MODULE="test_settings"
@@ -10,20 +10,32 @@ shift
 usage() {
     echo "USAGE: $PROG [command]"
     echo "  test - run the ratelimit tests"
-    echo "  flake8 - run flake8"
+    echo "  lint - run flake8 (alias: flake8)"
     echo "  shell - open the Django shell"
+    echo "  build - build a package for release"
+    echo "  check - run twine check on build artifacts"
     exit 1
 }
 
 case "$CMD" in
     "test" )
         echo "Django version: $(python -m django --version)"
-        python -m django test django_ratelimit "$@";;
-    "flake8" )
+        python -m django test django_ratelimit "$@"
+        ;;
+    "lint"|"flake8" )
         echo "Flake8 version: $(flake8 --version)"
-        flake8 "$@" django_ratelimit/;;
+        flake8 "$@" django_ratelimit/
+        ;;
     "shell" )
-        python -m django shell ;;
+        python -m django shell
+        ;;
+    "build" )
+        rm -rf dist/*
+        python -m build
+        ;;
+    "check" )
+        twine check dist/*
+        ;;
     * )
         usage ;;
 esac
diff --git a/setup.py b/setup.py
deleted file mode 100644
index 26d8966..0000000
--- a/setup.py
+++ /dev/null
@@ -1,41 +0,0 @@
-from setuptools import setup, find_packages
-
-from django_ratelimit import __version__
-
-
-setup(
-    name='django-ratelimit',
-    version=__version__,
-    description='Cache-based rate-limiting for Django.',
-    long_description=open('README.rst').read(),
-    author='James Socol',
-    author_email='me@jamessocol.com',
-    url='https://github.com/jsocol/django-ratelimit',
-    license='Apache Software License',
-    packages=find_packages(exclude=['test_settings']),
-    python_requires='>=3.4',
-    include_package_data=True,
-    package_data={'': ['README.rst']},
-    classifiers=[
-        'Development Status :: 5 - Production/Stable',
-        'Environment :: Web Environment',
-        'Framework :: Django',
-        'Framework :: Django :: 2.0',
-        'Framework :: Django :: 2.1',
-        'Framework :: Django :: 2.2',
-        'Framework :: Django :: 3.0',
-        'Intended Audience :: Developers',
-        'License :: OSI Approved :: Apache Software License',
-        'Operating System :: OS Independent',
-        'Programming Language :: Python',
-        'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5',
-        'Programming Language :: Python :: 3.6',
-        'Programming Language :: Python :: 3.7',
-        'Programming Language :: Python :: 3.8',
-        'Programming Language :: Python :: Implementation :: CPython',
-        'Programming Language :: Python :: Implementation :: PyPy',
-        'Topic :: Software Development :: Libraries :: Python Modules',
-    ]
-)