diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index a24b964b..2e335f7c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -8,7 +8,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-20.04, macos-11, windows-2019]
-        python-version: ["3.8", "3.9", "3.10", "3.11"]
+        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v3
@@ -21,7 +21,7 @@ jobs:
         set -x &&
 
         export DISTUTILS_DEBUG=1 &&
-        python -mpip install --upgrade pip setuptools &&
+        python -mpip install --upgrade pip &&
 
         case "$(python -c 'import sys; print(sys.platform)')" in
         linux)
diff --git a/src/_feature_tests.cpp b/ext/_feature_tests.cpp
similarity index 100%
rename from src/_feature_tests.cpp
rename to ext/_feature_tests.cpp
diff --git a/src/_macros.h b/ext/_macros.h
similarity index 100%
rename from src/_macros.h
rename to ext/_macros.h
diff --git a/src/_mplcairo.cpp b/ext/_mplcairo.cpp
similarity index 100%
rename from src/_mplcairo.cpp
rename to ext/_mplcairo.cpp
diff --git a/src/_mplcairo.h b/ext/_mplcairo.h
similarity index 100%
rename from src/_mplcairo.h
rename to ext/_mplcairo.h
diff --git a/src/_os.cpp b/ext/_os.cpp
similarity index 100%
rename from src/_os.cpp
rename to ext/_os.cpp
diff --git a/src/_os.h b/ext/_os.h
similarity index 100%
rename from src/_os.h
rename to ext/_os.h
diff --git a/src/_pattern_cache.cpp b/ext/_pattern_cache.cpp
similarity index 100%
rename from src/_pattern_cache.cpp
rename to ext/_pattern_cache.cpp
diff --git a/src/_pattern_cache.h b/ext/_pattern_cache.h
similarity index 100%
rename from src/_pattern_cache.h
rename to ext/_pattern_cache.h
diff --git a/src/_raqm.cpp b/ext/_raqm.cpp
similarity index 100%
rename from src/_raqm.cpp
rename to ext/_raqm.cpp
diff --git a/src/_raqm.h b/ext/_raqm.h
similarity index 100%
rename from src/_raqm.h
rename to ext/_raqm.h
diff --git a/src/_unity_build.cpp b/ext/_unity_build.cpp
similarity index 100%
rename from src/_unity_build.cpp
rename to ext/_unity_build.cpp
diff --git a/src/_util.cpp b/ext/_util.cpp
similarity index 100%
rename from src/_util.cpp
rename to ext/_util.cpp
diff --git a/src/_util.h b/ext/_util.h
similarity index 100%
rename from src/_util.h
rename to ext/_util.h
diff --git a/lib/mplcairo/.gitignore b/lib/mplcairo/.gitignore
deleted file mode 100644
index b39f7941..00000000
--- a/lib/mplcairo/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-*.dll
-_version.py
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 00000000..53e8dfbd
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,44 @@
+[build-system]
+requires = [
+    "setuptools>=62",
+    "setuptools_scm[toml]>=6.2",
+    "pybind11>=2.8.0",
+    "pycairo>=1.16.0; os_name == 'posix'",  # Removed for manylinux build.
+]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "mplcairo"
+description = "A (new) cairo backend for Matplotlib."
+readme = "README.rst"
+authors = [{name = "Antony Lee"}]
+license = {text = "MIT"}
+classifiers = [
+    "Development Status :: 4 - Beta",
+    "Framework :: Matplotlib",
+    "License :: OSI Approved :: MIT License",
+    "Programming Language :: Python :: 3",
+]
+requires-python = ">=3.8"
+dependencies = [
+    "matplotlib>=2.2",
+    "pillow",  # Already a dependency of mpl>=3.3.
+    "pycairo>=1.16.0; os_name == 'posix'",
+]
+dynamic = ["version"]
+
+[tool.setuptools_scm]
+version_scheme = "post-release"
+local_scheme = "node-and-date"
+fallback_version = "0+unknown"
+
+[tool.coverage.run]
+branch = true
+source_pkgs = ["mplcairo"]
+
+[tool.pytest.ini_options]
+filterwarnings = [
+    "error",
+    "ignore::DeprecationWarning",
+    "error::DeprecationWarning:mplcairo",
+]
diff --git a/setup.py b/setup.py
index 08c2572e..4bcac7f0 100644
--- a/setup.py
+++ b/setup.py
@@ -5,7 +5,7 @@
 Environment variables:
 
 MPLCAIRO_MANYLINUX
-    If set, build a manylinux wheel: pycairo is not declared as setup_requires.
+    If set, build a manylinux wheel: pycairo is not a build requirement.
 
 MPLCAIRO_NO_UNITY_BUILD
     If set, compile the various cpp files separately, instead of as a single
@@ -23,22 +23,21 @@
 import subprocess
 from subprocess import CalledProcessError
 import sys
+from tempfile import TemporaryDirectory
+import tokenize
 import urllib.request
 
-if sys.platform == "darwin":
-    os.environ.setdefault("CC", "clang")
-    # Funnily enough, distutils uses $CC to compile c++ extensions but
-    # $CXX to *link* such extensions...  (Moreover, it does some funky
-    # changes to $CXX if either $CC or $CXX has multiple words -- see e.g.
-    # https://bugs.python.org/issue6863.)
-    os.environ.setdefault("CXX", "clang")
-
-from setupext import Extension, build_ext, find_packages, setup
+import setuptools
+from setuptools import Distribution
+from pybind11.setup_helpers import Pybind11Extension
+if os.environ.get("MPLCAIRO_MANYLINUX", ""):
+    cairo = None
+else:
+    import cairo
 
 
 MIN_CAIRO_VERSION = "1.13.1"  # Also in _feature_tests.cpp.
 MIN_RAQM_VERSION = "0.7.0"
-MANYLINUX = bool(os.environ.get("MPLCAIRO_MANYLINUX", ""))
 UNITY_BUILD = not bool(os.environ.get("MPLCAIRO_NO_UNITY_BUILD"))
 
 
@@ -47,6 +46,63 @@ def get_pkgconfig(*args):
                                                universal_newlines=True))
 
 
+def gen_extension(tmpdir):
+    ext = Pybind11Extension(
+        "mplcairo._mplcairo",
+        sources=(
+            ["ext/_unity_build.cpp"] if UNITY_BUILD else
+            sorted({*map(str, Path("ext").glob("*.cpp"))}
+                   - {"ext/_unity_build.cpp"})),
+        depends=[
+            "setup.py",
+            *map(str, Path("ext").glob("*.h")),
+            *map(str, Path("ext").glob("*.cpp")),
+        ],
+        cxx_std=17,
+        include_dirs=[cairo.get_include()] if cairo else [],
+    )
+
+    # NOTE: Versions <= 8.2 of Arch Linux's python-pillow package included
+    # *into a non-overridable distutils header directory* a ``raqm.h`` that
+    # is both invalid (https://bugs.archlinux.org/task/57492) and outdated
+    # (missing a declaration for `raqm_version_string`).  It is thus not
+    # possible to build mplcairo with such an old distro package installed.
+    try:
+        get_pkgconfig(f"raqm >= {MIN_RAQM_VERSION}")
+    except (FileNotFoundError, CalledProcessError):
+        tmpdir.mkdir(parents=True, exist_ok=True)
+        (tmpdir / "raqm-version.h").write_text("")  # Touch it.
+        with urllib.request.urlopen(
+                f"https://raw.githubusercontent.com/HOST-Oman/libraqm/"
+                f"v{MIN_RAQM_VERSION}/ext/raqm.h") as request, \
+                (tmpdir / "raqm.h").open("wb") as file:
+            file.write(request.read())
+        ext.include_dirs += [tmpdir]
+    else:
+        ext.extra_compile_args += get_pkgconfig("--cflags", "raqm")
+
+    if os.name == "posix":
+        get_pkgconfig(f"cairo >= {MIN_CAIRO_VERSION}")
+        ext.extra_compile_args += [
+            "-flto", "-Wall", "-Wextra", "-Wpedantic",
+            *get_pkgconfig("--cflags", "cairo"),
+        ]
+        ext.extra_link_args += ["-flto"]
+
+    elif os.name == "nt":
+        # Windows conda path for FreeType.
+        ext.include_dirs += [Path(sys.prefix, "Library/include")]
+        ext.extra_compile_args += [
+            "/experimental:preprocessor",
+            "/wd4244", "/wd4267",  # cf. gcc -Wconversion.
+        ]
+        ext.libraries += ["psapi", "cairo", "freetype"]
+        # Windows conda path for FreeType -- needs to be str, not Path.
+        ext.library_dirs += [str(Path(sys.prefix, "Library/lib"))]
+
+    return ext
+
+
 @functools.lru_cache(1)
 def paths_from_link_libpaths():
     # "Easy" way to call CommandLineToArgvW...
@@ -61,69 +117,7 @@ def paths_from_link_libpaths():
     return paths
 
 
-class build_ext(build_ext):
-
-    def finalize_options(self):
-        import cairo
-        from pybind11.setup_helpers import Pybind11Extension
-
-        self.distribution.ext_modules[:] = ext, = [Pybind11Extension(
-            "mplcairo._mplcairo",
-            sources=(
-                ["src/_unity_build.cpp"] if UNITY_BUILD else
-                sorted({*map(str, Path("src").glob("*.cpp"))}
-                       - {"src/_unity_build.cpp"})),
-            depends=[
-                "setup.py",
-                *map(str, Path("src").glob("*.h")),
-                *map(str, Path("src").glob("*.cpp")),
-            ],
-            cxx_std=17,
-            include_dirs=[cairo.get_include()],
-        )]
-
-        # NOTE: Versions <= 8.2 of Arch Linux's python-pillow package included
-        # *into a non-overridable distutils header directory* a ``raqm.h`` that
-        # is both invalid (https://bugs.archlinux.org/task/57492) and outdated
-        # (missing a declaration for `raqm_version_string`).  It is thus not
-        # possible to build mplcairo with such an old distro package installed.
-        try:
-            get_pkgconfig(f"raqm >= {MIN_RAQM_VERSION}")
-        except (FileNotFoundError, CalledProcessError):
-            tmp_include_dir = Path(
-                self.get_finalized_command("build").build_base, "include")
-            tmp_include_dir.mkdir(parents=True, exist_ok=True)
-            (tmp_include_dir / "raqm-version.h").write_text("")  # Touch it.
-            with urllib.request.urlopen(
-                    f"https://raw.githubusercontent.com/HOST-Oman/libraqm/"
-                    f"v{MIN_RAQM_VERSION}/src/raqm.h") as request, \
-                 (tmp_include_dir / "raqm.h").open("wb") as file:
-                file.write(request.read())
-            ext.include_dirs += [tmp_include_dir]
-        else:
-            ext.extra_compile_args += get_pkgconfig("--cflags", "raqm")
-
-        if os.name == "posix":
-            get_pkgconfig(f"cairo >= {MIN_CAIRO_VERSION}")
-            ext.extra_compile_args += [
-                "-flto", "-Wall", "-Wextra", "-Wpedantic",
-                *get_pkgconfig("--cflags", "cairo"),
-            ]
-            ext.extra_link_args += ["-flto"]
-
-        elif os.name == "nt":
-            # Windows conda path for FreeType.
-            ext.include_dirs += [Path(sys.prefix, "Library/include")]
-            ext.extra_compile_args += [
-                "/experimental:preprocessor",
-                "/wd4244", "/wd4267",  # cf. gcc -Wconversion.
-            ]
-            ext.libraries += ["psapi", "cairo", "freetype"]
-            # Windows conda path for FreeType -- needs to be str, not Path.
-            ext.library_dirs += [str(Path(sys.prefix, "Library/lib"))]
-
-        super().finalize_options()
-
+class build_ext(setuptools.command.build_ext.build_ext):
     def _copy_dlls_to(self, dest):
         if os.name == "nt":
             for dll in ["cairo.dll", "freetype.dll"]:
@@ -142,41 +136,41 @@ def copy_extensions_to_source(self):
             self.get_finalized_command("build_py").get_package_dir("mplcairo"))
 
 
-setup.register_pth_hook("setup_mplcairo_pth.py", "mplcairo.pth")
-
-
-setup(
-    name="mplcairo",
-    description="A (new) cairo backend for Matplotlib.",
-    long_description=open("README.rst", encoding="utf-8").read(),
-    author="Antony Lee",
-    url="https://github.com/matplotlib/mplcairo",
-    license="MIT",
-    classifiers=[
-        "Development Status :: 4 - Beta",
-        "Framework :: Matplotlib",
-        "License :: OSI Approved :: MIT License",
-        "Programming Language :: Python :: 3",
-    ],
-    cmdclass={"build_ext": build_ext},
-    packages=find_packages("lib"),
-    package_dir={"": "lib"},
-    ext_modules=[Extension("", [])],
-    python_requires=">=3.8",
-    setup_requires=[
-        "setuptools>=36.7",  # setup_requires early install.
-        "setuptools_scm",
-        "pybind11>=2.8.0",
-        *(["pycairo>=1.16.0; os_name == 'posix'"] if not MANYLINUX else []),
-    ],
-    use_scm_version={  # xref __init__.py
-        "version_scheme": "post-release",
-        "local_scheme": "node-and-date",
-        "write_to": "lib/mplcairo/_version.py",
-    },
-    install_requires=[
-        "matplotlib>=2.2",
-        "pillow",  # Already a dependency of mpl>=3.3.
-        "pycairo>=1.16.0; os_name == 'posix'",
-    ],
-)
+def register_pth_hook(source_path, pth_name):
+    """
+    ::
+        setup.register_pth_hook("hook_source.py", "hook_name.pth")  # Add hook.
+    """
+    with tokenize.open(source_path) as file:
+        source = file.read()
+    _pth_hook_mixin._pth_hooks.append((pth_name, source))
+
+
+class _pth_hook_mixin:
+    _pth_hooks = []
+
+    def run(self):
+        super().run()
+        for pth_name, source in self._pth_hooks:
+            with Path(self.install_dir, pth_name).open("w") as file:
+                file.write(f"import os; exec({source!r})")
+
+    def get_outputs(self):
+        return (super().get_outputs()
+                + [str(Path(self.install_dir, pth_name))
+                   for pth_name, _ in self._pth_hooks])
+
+
+def setup(**kwargs):
+    cmdclass = kwargs.setdefault("cmdclass", {})
+    get = Distribution({"cmdclass": cmdclass}).get_command_class
+    cmdclass["develop"] = type(
+        "develop_with_pth_hook", (_pth_hook_mixin, get("develop")), {})
+    cmdclass["install_lib"] = type(
+        "install_lib_with_pth_hook", (_pth_hook_mixin, get("install_lib")), {})
+    setuptools.setup(**kwargs)
+
+
+register_pth_hook("setup_mplcairo_pth.py", "mplcairo.pth")
+with TemporaryDirectory() as tmpdir:
+    setup(ext_modules=[gen_extension(tmpdir=Path(tmpdir))])
diff --git a/setupext.py b/setupext.py
deleted file mode 100644
index 0650d441..00000000
--- a/setupext.py
+++ /dev/null
@@ -1,60 +0,0 @@
-from pathlib import Path
-import tokenize
-
-import setuptools
-from setuptools import Distribution, Extension, find_packages
-from setuptools.command.build_ext import build_ext
-
-
-__all__ = ["Extension", "build_ext", "find_packages", "setup"]
-
-
-class build_ext(build_ext):
-    def build_extensions(self):
-        try:
-            self.compiler.compiler_so.remove("-Wstrict-prototypes")
-        except (AttributeError, ValueError):
-            pass
-        super().build_extensions()
-
-
-def register_pth_hook(source_path, pth_name):
-    """
-    ::
-        setup.register_pth_hook("hook_source.py", "hook_name.pth")  # Add hook.
-    """
-    with tokenize.open(source_path) as file:
-        source = file.read()
-    _pth_hook_mixin._pth_hooks.append((pth_name, source))
-
-
-class _pth_hook_mixin:
-    _pth_hooks = []
-
-    def run(self):
-        super().run()
-        for pth_name, source in self._pth_hooks:
-            with Path(self.install_dir, pth_name).open("w") as file:
-                file.write(f"import os; exec({source!r})")
-
-    def get_outputs(self):
-        return (super().get_outputs()
-                + [str(Path(self.install_dir, pth_name))
-                   for pth_name, _ in self._pth_hooks])
-
-
-def _prepare_pth_hook(kwargs):
-    cmdclass = kwargs.setdefault("cmdclass", {})
-    get = Distribution({"cmdclass": cmdclass}).get_command_class
-    cmdclass["develop"] = type(
-        "develop_with_pth_hook", (_pth_hook_mixin, get("develop")), {})
-    cmdclass["install_lib"] = type(
-        "install_lib_with_pth_hook", (_pth_hook_mixin, get("install_lib")), {})
-
-
-def setup(**kwargs):
-    _prepare_pth_hook(kwargs)
-    setuptools.setup(**kwargs)
-
-
-setup.register_pth_hook = register_pth_hook
diff --git a/src/mplcairo/.gitignore b/src/mplcairo/.gitignore
new file mode 100644
index 00000000..6a746131
--- /dev/null
+++ b/src/mplcairo/.gitignore
@@ -0,0 +1 @@
+*.dll
diff --git a/lib/mplcairo/__init__.py b/src/mplcairo/__init__.py
similarity index 100%
rename from lib/mplcairo/__init__.py
rename to src/mplcairo/__init__.py
diff --git a/lib/mplcairo/_backports.py b/src/mplcairo/_backports.py
similarity index 100%
rename from lib/mplcairo/_backports.py
rename to src/mplcairo/_backports.py
diff --git a/lib/mplcairo/_util.py b/src/mplcairo/_util.py
similarity index 100%
rename from lib/mplcairo/_util.py
rename to src/mplcairo/_util.py
diff --git a/src/mplcairo/_version.py b/src/mplcairo/_version.py
new file mode 100644
index 00000000..691ec840
--- /dev/null
+++ b/src/mplcairo/_version.py
@@ -0,0 +1,16 @@
+# file generated by setuptools_scm
+# don't change, don't track in version control
+TYPE_CHECKING = False
+if TYPE_CHECKING:
+    from typing import Tuple, Union
+    VERSION_TUPLE = Tuple[Union[int, str], ...]
+else:
+    VERSION_TUPLE = object
+
+version: str
+__version__: str
+__version_tuple__: VERSION_TUPLE
+version_tuple: VERSION_TUPLE
+
+__version__ = version = '0.5.post32+ge771c74'
+__version_tuple__ = version_tuple = (0, 5, 'ge771c74')
diff --git a/lib/mplcairo/base.py b/src/mplcairo/base.py
similarity index 100%
rename from lib/mplcairo/base.py
rename to src/mplcairo/base.py
diff --git a/lib/mplcairo/gtk.py b/src/mplcairo/gtk.py
similarity index 100%
rename from lib/mplcairo/gtk.py
rename to src/mplcairo/gtk.py
diff --git a/lib/mplcairo/gtk_native.py b/src/mplcairo/gtk_native.py
similarity index 100%
rename from lib/mplcairo/gtk_native.py
rename to src/mplcairo/gtk_native.py
diff --git a/lib/mplcairo/macosx.py b/src/mplcairo/macosx.py
similarity index 100%
rename from lib/mplcairo/macosx.py
rename to src/mplcairo/macosx.py
diff --git a/lib/mplcairo/multipage.py b/src/mplcairo/multipage.py
similarity index 100%
rename from lib/mplcairo/multipage.py
rename to src/mplcairo/multipage.py
diff --git a/lib/mplcairo/qt.py b/src/mplcairo/qt.py
similarity index 100%
rename from lib/mplcairo/qt.py
rename to src/mplcairo/qt.py
diff --git a/lib/mplcairo/tk.py b/src/mplcairo/tk.py
similarity index 100%
rename from lib/mplcairo/tk.py
rename to src/mplcairo/tk.py
diff --git a/lib/mplcairo/wx.py b/src/mplcairo/wx.py
similarity index 100%
rename from lib/mplcairo/wx.py
rename to src/mplcairo/wx.py
diff --git a/tools/build-macos-wheel.sh b/tools/build-macos-wheel.sh
index 8667f53c..ac8f9f22 100755
--- a/tools/build-macos-wheel.sh
+++ b/tools/build-macos-wheel.sh
@@ -18,9 +18,9 @@ python -mvenv "$tmpenv"
 
 (
     source "$tmpenv/bin/activate"
-    python -mpip install --upgrade pip setuptools wheel delocate
+    python -mpip install --upgrade pip build delocate setuptools_scm
 
-    cd "$toplevel"
-    python setup.py bdist_wheel
-    delocate-wheel -v dist/*
+    cd "$tmpdir/mplcairo"
+    python -mbuild
+    python -mdelocate.cmd.delocate_wheel -v dist/*
 )
diff --git a/tools/build-manylinux-wheel.sh b/tools/build-manylinux-wheel.sh
index 7fcc93ac..af6db211 100755
--- a/tools/build-manylinux-wheel.sh
+++ b/tools/build-manylinux-wheel.sh
@@ -14,17 +14,20 @@ if [[ "$MPLCAIRO_MANYLINUX" != 1 ]]; then
     tmpdir="$(mktemp -d)"
     trap 'rm -rf "$tmpdir"' EXIT INT TERM
     git clone "$toplevel" "$tmpdir/mplcairo"
+    python -mvenv "$tmpdir/tmpenv"
+    "$tmpdir/tmpenv/bin/python" -mpip install setuptools_scm
+    mplcairo_version="$("$tmpdir/tmpenv/bin/python" -msetuptools_scm)"
+    sed -i '/Removed for manylinux build/d' "$tmpdir/mplcairo/pyproject.toml"
     relpath="$(
         python -c 'import os, sys; print(os.path.relpath(*map(os.path.realpath, sys.argv[1:])))' \
             "$0" "$toplevel")"
     ${DOCKER:-docker} run \
-        -e MPLCAIRO_MANYLINUX=1 -e PY_VERS="${PY_VERS:-3.7 3.8 3.9 3.10 3.11}" \
+        -e MPLCAIRO_MANYLINUX=1 -e PY_VERS="${PY_VERS:-3.8 3.9 3.10 3.11 3.12}" \
+        -e mplcairo_version="$mplcairo_version" \
         --volume "$tmpdir/mplcairo":/io/mplcairo:Z \
         quay.io/pypa/manylinux2014_x86_64 \
         "/io/mplcairo/$relpath"
 
-    user="${SUDO_USER:-$USER}"
-    chown "$user:$(id -gn "$user")" -R "$tmpdir/mplcairo/build"
     mkdir -p "$toplevel/dist"
     mv "$tmpdir/mplcairo/dist/"*-manylinux*.whl "$toplevel/dist"
 
@@ -63,16 +66,14 @@ else
         py_prefix=("/opt/python/cp${py_ver/./}-"*)
         tags="$(basename "$py_prefix")"
         echo "Building the wheel for Python $py_ver."
-        # Shim access to pycairo's header.
-        echo 'def get_include(): return "/dev/null"' \
-            >"$py_prefix/lib/python$py_ver/site-packages/cairo.py"
         (
             cd /io/mplcairo
+            "$py_prefix/bin/python" -mpip install build
             # Force a rebuild of the extension.
-            CFLAGS="-static-libgcc -static-libstdc++ -I/usr/include/cairo -I/usr/include/freetype2" \
+            SETUPTOOLS_SCM_PRETEND_VERSION_FOR_MPLCAIRO="$mplcairo_version" \
+                CFLAGS="-static-libgcc -static-libstdc++ -I/usr/include/cairo -I/usr/include/freetype2" \
                 LDFLAGS="-static-libgcc -static-libstdc++" \
-                "$py_prefix/bin/python" setup.py bdist_wheel
-            mplcairo_version="$("$py_prefix/bin/python" setup.py --version)"
+                "$py_prefix/bin/python" -mbuild
             for wheel in "dist/mplcairo-$mplcairo_version-$tags-"*".whl"; do
                 auditwheel -v repair -wdist "$wheel"
                 rm "$wheel"