diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index ef6b82d3..d613e7bc 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -26,7 +26,4 @@ formats: []
 # Optionally declare the Python requirements required to build your docs
 python:
   install:
-  - method: pip
-    path: .
-    extra_requirements:
-    - docs
+  - requirements: docs/requirements.txt
diff --git a/Makefile b/Makefile
deleted file mode 100644
index f49c3c93..00000000
--- a/Makefile
+++ /dev/null
@@ -1,51 +0,0 @@
-HERE = $(shell pwd)
-BIN = $(HERE)/bin
-PYTHON = $(BIN)/python
-INSTALL = $(BIN)/pip install
-TOX_VENV ?= py37
-BUILD_DIRS = bin build include lib lib64 man share
-
-PYTHON_EXE = $(shell [ -f $(PYTHON) ] && echo $(PYTHON) || echo python)
-PYPY = $(shell $(PYTHON_EXE) -c "import sys; print(getattr(sys, 'pypy_version_info', False) and 'yes' or 'no')")
-CI ?= false
-CI_PYTHON_VERSION ?= $(shell $(PYTHON_EXE) -c "import sys; print('.'.join([str(s) for s in sys.version_info][:2]))")
-
-GREENLET_SUPPORTED = yes
-ifeq ($(findstring 3.,$(CI_PYTHON_VERSION)), 3.)
-	GREENLET_SUPPORTED = no
-	VENV_CMD = $(PYTHON_EXE) -m venv .
-else
-	VENV_CMD = $(PYTHON_EXE) -m virtualenv .
-endif
-ifeq ($(PYPY),yes)
-	GREENLET_SUPPORTED = no
-endif
-
-.PHONY: all build clean test
-
-all: build
-
-$(PYTHON):
-	$(VENV_CMD)
-
-build: $(PYTHON)
-ifeq ($(GREENLET_SUPPORTED),yes)
-	$(INSTALL) -U -r requirements_eventlet.txt
-	$(INSTALL) -U -r requirements_gevent.txt
-endif
-ifneq ($(CI), true)
-	$(INSTALL) -U -r requirements_sphinx.txt
-endif
-	$(INSTALL) -U -r requirements.txt
-	$(PYTHON) setup.py develop
-	$(INSTALL) kazoo[test]
-
-clean:
-	rm -rf $(BUILD_DIRS)
-
-test:
-	tox -e$(TOX_VENV)
-
-html:
-	cd docs && \
-	make html
diff --git a/constraints.txt b/constraints.txt
deleted file mode 100644
index 58be5adb..00000000
--- a/constraints.txt
+++ /dev/null
@@ -1,19 +0,0 @@
-# Consistent testing environment.
-# requirements.txt
-eventlet>=0.17.1 ; implementation_name!='pypy'
-gevent>=1.2 ; implementation_name!='pypy'
-
-# requirements-dev.txt
-black==22.10.0
-coverage==6.3.2; python_version=="3.8"
-coverage==7.10.7; python_version > "3.8"
-flake8==5.0.2
-mypy==1.14.1
-objgraph==3.5.0
-pytest==6.2.5; python_version=="3.8"
-pytest==8.4.2; python_version > "3.8"
-pytest-cov==3.0.0; python_version=="3.8"
-pytest-cov==7.0.0; python_version > "3.8"
-pytest-timeout==2.2.0; python_version=="3.8"
-pytest-timeout==2.4.0; python_version > "3.8"
-pyOpenSSL<26.2.0
diff --git a/docs/requirements.txt b/docs/requirements.txt
new file mode 100644
index 00000000..86410a8f
--- /dev/null
+++ b/docs/requirements.txt
@@ -0,0 +1,2 @@
+Sphinx>=1.2.2
+sphinx-autodoc-typehints>=1
diff --git a/pyproject.toml b/pyproject.toml
index 869ed27c..1f382f17 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,9 +1,98 @@
 [build-system]
 build-backend = 'setuptools.build_meta'
 requires = [
-    'setuptools >= 46.4.0',
+    'setuptools >= 61.0.0',
 ]
 
+[project]
+name = "kazoo"
+dynamic = ["version", "readme"]
+description = "Higher Level Zookeeper Client"
+requires-python = ">=3.8"
+license = {text = "Apache 2.0"}
+authors = [
+    {name = "Kazoo team", email = "python-zk@googlegroups.com"},
+]
+keywords = ["zookeeper", "lock", "leader", "configuration"]
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "License :: OSI Approved :: Apache Software License",
+    "Intended Audience :: Developers",
+    "Operating System :: OS Independent",
+    "Programming Language :: Python",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: 3.14",
+    "Programming Language :: Python :: Implementation :: CPython",
+    "Programming Language :: Python :: Implementation :: PyPy",
+    "Topic :: Communications",
+    "Topic :: System :: Distributed Computing",
+    "Topic :: System :: Networking",
+]
+dependencies = ["typing-extensions"]
+
+[project.urls]
+Documentation = "https://kazoo.readthedocs.io"
+Changelog = "https://github.com/python-zk/kazoo/releases"
+Source = "https://github.com/python-zk/kazoo"
+"Bug Tracker" = "https://github.com/python-zk/kazoo/issues"
+
+[project.optional-dependencies]
+eventlet = ["eventlet>=0.17.1; implementation_name != 'pypy'"]
+gevent = ["gevent>=1.2; implementation_name != 'pypy'"]
+sasl = ["pure_sasl>=0.5.1"]
+
+[dependency-groups]
+black = ["black==22.10.0"]
+pep8 = ["flake8==5.0.2"]
+test-extras = [
+    "objgraph==3.5.0",
+    "pyOpenSSL<26.2.0",
+    "pyjks",
+    "unittest-parametrize",
+]
+pytest = [
+    "pytest==7.4.4; python_version == '3.8'",
+    "pytest==8.4.2; python_version > '3.8'",
+]
+test = [
+    "coverage==6.3.2; python_version == '3.8'",
+    "coverage==7.10.7; python_version > '3.8'",
+    {include-group = "pytest"},
+    "pytest-cov==3.0.0; python_version == '3.8'",
+    "pytest-cov==7.0.0; python_version > '3.8'",
+    "pytest-timeout==2.2.0; python_version == '3.8'",
+    "pytest-timeout==2.4.0; python_version > '3.8'",
+    {include-group = "test-extras"},
+]
+mypy = [
+    "mypy==1.14.1",
+    {include-group = "test-extras"},
+    {include-group = "pytest"},
+    "types-gevent",
+    "types-mock",
+    "types-objgraph",
+    "types-pyjks",
+]
+
+[tool.setuptools]
+zip-safe = false
+include-package-data = true
+packages = {find = {}}
+license-files = ["LICENSE"]
+
+[tool.setuptools.package-data]
+kazoo = ["py.typed"]
+
+[tool.setuptools.dynamic]
+version = {attr = "kazoo.version.__version__"}
+readme = {file = ["README.md", "CHANGES.md"], content-type = "text/markdown"}
+
 [tool.black]
 line-length = 79
 # We need a later version of black for 312-314
diff --git a/setup.cfg b/setup.cfg
index 5ef8ffb2..3c2fdf51 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,106 +1,2 @@
-[metadata]
-name = kazoo
-version = attr: kazoo.version.__version__
-author = Kazoo team
-author_email = python-zk@googlegroups.com
-url = https://kazoo.readthedocs.io
-description = "Higher Level Zookeeper Client"
-long_description = file: README.md, CHANGES.md
-long_description_content_type = text/markdown
-license = Apache 2.0
-license_files =
-    LICENSE
-platform = any
-keywords = zookeeper, lock, leader, configuration
-classifiers =
-    Development Status :: 5 - Production/Stable
-    License :: OSI Approved :: Apache Software License
-    Intended Audience :: Developers
-    Operating System :: OS Independent
-    Programming Language :: Python
-    Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.8
-    Programming Language :: Python :: 3.9
-    Programming Language :: Python :: 3.10
-    Programming Language :: Python :: 3.11
-    Programming Language :: Python :: 3.12
-    Programming Language :: Python :: 3.13
-    Programming Language :: Python :: 3.14
-    Programming Language :: Python :: Implementation :: CPython
-    Programming Language :: Python :: Implementation :: PyPy
-    Topic :: Communications
-    Topic :: System :: Distributed Computing
-    Topic :: System :: Networking
-project_urls =
-    Documentation = https://kazoo.readthedocs.io
-    Changelog = https://github.com/python-zk/kazoo/releases
-    Source = https://github.com/python-zk/kazoo
-    Bug Tracker = https://github.com/python-zk/kazoo/issues
-
-
-[options]
-zip_safe = false
-include_package_data = true
-packages = find:
-install_requires =
-    typing-extensions
-
-[options.package_data]
-kazoo = py.typed
-
-[aliases]
-release = sdist bdist_wheel
-
 [egg_info]
 tag_build = dev
-
-[options.extras_require]
-dev =
-    black
-    flake8
-
-# I have to pin this HERE because I can't persuade vscode to
-# look in constraints.txt
-other =
-    pyOpenSSL<26.2.0
-    typing-extensions
-
-test =
-    objgraph
-    pytest
-    pytest-cov
-    pytest-timeout
-    gevent>=1.2 ; implementation_name!='pypy'
-    eventlet>=0.17.1 ; implementation_name!='pypy'
-    pyjks
-    unittest-parametrize
-    %(other)s
-
-eventlet =
-    eventlet>=0.17.1
-
-gevent =
-    gevent>=1.2
-
-sasl =
-    pure_sasl>=0.5.1
-
-docs =
-    Sphinx>=1.2.2
-    sphinx-autodoc-typehints>=1
-
-typing =
-    mypy==1.14.1
-    types-gevent
-    types-mock
-    types-objgraph
-    types-pyjks
-
-alldeps =
-    %(dev)s
-    %(eventlet)s
-    %(gevent)s
-    %(sasl)s
-    %(docs)s
-    %(other)s
-    %(typing)s
diff --git a/tox.ini b/tox.ini
index ab62ae26..cafa16e0 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
-minversion = 4.3.4
 requires=
+    tox>=4.22
     virtualenv>=20.7.2
 skip_missing_interpreters=True
 envlist =
@@ -13,7 +13,7 @@ isolated_build = true
 [testenv]
 wheel = True
 wheel_build_env = build
-install_command = pip install -c{toxinidir}/constraints.txt {opts} {packages}
+install_command = pip install {opts} {packages}
 passenv =
     CI
     TOX_*
@@ -21,9 +21,9 @@ passenv =
     ZOOKEEPER_*
 setenv =
     pypy3: PYPY=1
-extras =
+dependency_groups =
     test
-    docs: docs
+extras =
     gevent: gevent
     eventlet: eventlet
     sasl: sasl
@@ -41,27 +41,27 @@ commands =
 
 [testenv:build]
 
-[testenv:pep8]
-extras = alldeps
+[testenv:docs]
+dependency_groups =
 deps =
-    flake8
+    -r{toxinidir}/docs/requirements.txt
+commands = sphinx-build -b html docs {toxworkdir}/docs/html
+
+[testenv:pep8]
+dependency_groups = pep8
 usedevelop = True
 commands = flake8 {posargs} {toxinidir}/kazoo
 
 [testenv:black]
-extras =
-deps =
-    black
+dependency_groups = black
 usedevelop = True
 commands = black --check {posargs: {toxinidir}/kazoo {toxinidir}/kazoo}
 
 [testenv:mypy]
-extras = alldeps
-deps =
-    mypy
-    types-mock
-    pyopenssl
-    pytest
-    unittest-parametrize
+dependency_groups = mypy
+extras =
+    eventlet
+    gevent
+    sasl
 usedevelop = True
 commands = mypy --config-file {toxinidir}/pyproject.toml {toxinidir}/kazoo