diff --git a/.github/workflows/publish_to_pypi.yml b/.github/workflows/publish_to_pypi.yml
index 09b2c0e2..01a0a846 100644
--- a/.github/workflows/publish_to_pypi.yml
+++ b/.github/workflows/publish_to_pypi.yml
@@ -20,7 +20,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install setuptools wheel twine
+          pip install build setuptools wheel twine
       - name: Determine version from git tag
         id: version
         run: echo "tag=${GITHUB_REF#refs/*/}" >> $GITHUB_OUTPUT
diff --git a/.gitignore b/.gitignore
index 91d94902..cb13f8bf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -73,3 +73,5 @@ tests/approved_files/VerifyTests.test_verify_automatic_approval.approved.txt
 junit-reports/TEST-results.xml
 
 .ignore/
+
+/setup.py
diff --git a/mypy.ini b/mypy.ini
index 1e082493..ef1a27ff 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -15,6 +15,7 @@ exclude = (?x)(
     ^build/ |
     ^dist/ |
     ^setup/ |
+    ^setup\.py$ |
     ^\.tox/ |
     ^\.venv/ |
     ^venv.*/
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 00000000..9787c3bd
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,3 @@
+[build-system]
+requires = ["setuptools", "wheel"]
+build-backend = "setuptools.build_meta"
diff --git a/requirements.dev.txt b/requirements.dev.txt
index 91eb4796..fd282d51 100644
--- a/requirements.dev.txt
+++ b/requirements.dev.txt
@@ -1,5 +1,6 @@
 -r requirements.prod.txt
 -r requirements.test.txt
+build
 ruff
 setuptools
 mypy
diff --git a/setup/publish_approval_utilities.sh b/setup/publish_approval_utilities.sh
index 4711d4a9..96a1a42f 100755
--- a/setup/publish_approval_utilities.sh
+++ b/setup/publish_approval_utilities.sh
@@ -1,5 +1,7 @@
 #!/bin/sh
 
-python setup/setup.approval_utilities.py sdist bdist_wheel
+cp setup/setup.approval_utilities.py setup.py
+python -m build .
+rm setup.py
 twine upload --repository-url ${TWINE_REPOSITORY_URL} dist/*
 rm -r dist
diff --git a/setup/publish_approvaltests.sh b/setup/publish_approvaltests.sh
index e3bf217e..82b931f6 100755
--- a/setup/publish_approvaltests.sh
+++ b/setup/publish_approvaltests.sh
@@ -1,5 +1,7 @@
-#! /bin/sh
+#!/bin/sh
 
-python setup/setup.publish.py sdist bdist_wheel
+cp setup/setup.publish.py setup.py
+python -m build .
+rm setup.py
 twine upload --repository-url ${TWINE_REPOSITORY_URL} dist/*
 rm -r dist
diff --git a/setup/publish_minimal.sh b/setup/publish_minimal.sh
index 28ddee00..60897c41 100755
--- a/setup/publish_minimal.sh
+++ b/setup/publish_minimal.sh
@@ -1,5 +1,7 @@
-#! /bin/sh
+#!/bin/sh
 
-python setup/setup.minimal.py sdist bdist_wheel
+cp setup/setup.minimal.py setup.py
+python -m build .
+rm setup.py
 twine upload --repository-url ${TWINE_REPOSITORY_URL} dist/*
 rm -r dist
diff --git a/setup/setup.approval_utilities.py b/setup/setup.approval_utilities.py
index ac16bf75..948ccd0a 100644
--- a/setup/setup.approval_utilities.py
+++ b/setup/setup.approval_utilities.py
@@ -1,8 +1,13 @@
+import sys
+from pathlib import Path
 from typing import Any, Dict
-
-from setup_utils import get_version
 from setuptools import find_packages, setup
 
+_setup_dir = Path(__file__).resolve().parent / "setup"
+if _setup_dir.is_dir():
+    sys.path.insert(0, str(_setup_dir))
+from setup_utils import get_version  # pylint: disable=wrong-import-position
+
 requires: Dict[str, Any] = {}
 setup(
     name="approval_utilities",
diff --git a/setup/setup.minimal.py b/setup/setup.minimal.py
index 920b4542..497d69f1 100644
--- a/setup/setup.minimal.py
+++ b/setup/setup.minimal.py
@@ -1,3 +1,9 @@
+import sys
+from pathlib import Path
+
+_setup_dir = Path(__file__).resolve().parent / "setup"
+if _setup_dir.is_dir():
+    sys.path.insert(0, str(_setup_dir))
 from setup_utils import do_the_setup, get_requirements_from_file
 
 required = get_requirements_from_file("../requirements.prod.required.txt")
diff --git a/setup/setup.publish.py b/setup/setup.publish.py
index 12255b2d..74d25e35 100644
--- a/setup/setup.publish.py
+++ b/setup/setup.publish.py
@@ -1,6 +1,10 @@
-from setup_utils import get_requirements_from_file, get_version
+import sys
+from pathlib import Path
 
-from setup import do_the_setup
+_setup_dir = Path(__file__).resolve().parent / "setup"
+if _setup_dir.is_dir():
+    sys.path.insert(0, str(_setup_dir))
+from setup_utils import do_the_setup, get_requirements_from_file, get_version
 
 required = get_requirements_from_file("../requirements.prod.required.txt")
 required += get_requirements_from_file("../requirements.prod.extras.txt")
diff --git a/setup/setup.py b/setup/setup.py
deleted file mode 100644
index 898b464f..00000000
--- a/setup/setup.py
+++ /dev/null
@@ -1,11 +0,0 @@
-from setup_utils import do_the_setup, get_requirements_from_file
-
-required = get_requirements_from_file("../requirements.prod.required.txt")
-required += get_requirements_from_file("../requirements.prod.extras.txt")
-
-do_the_setup(
-    package_name="approvaltests",
-    package_description="Assertion/verification library to aid testing",
-    required=required,
-    extra_requires={},
-)
diff --git a/test__mypy_accepts_our_packages.py b/test__mypy_accepts_our_packages.py
index 8d01e931..ec46ddb7 100644
--- a/test__mypy_accepts_our_packages.py
+++ b/test__mypy_accepts_our_packages.py
@@ -1,35 +1,38 @@
+import glob
 import pathlib
+import shutil
 import subprocess
 import sys
 import tempfile
 import time
 import typing
 
-from version import version_number
-
 
 def main() -> None:
     for package_name, setup_file in [
         ("approval_utilities", "setup/setup.approval_utilities.py"),
-        ("approvaltests", "setup/setup.py"),
+        ("approvaltests", "setup/setup.publish.py"),
     ]:
-        build_number = str(int(time.time()))
-        _run_python_checked(
-            [
-                setup_file,
-                "--quiet",
-                "bdist_wheel",
-                "--build-number",
-                build_number,
-            ]
-        )
+        print(f"Testing build {package_name} ...")
+        dist_dir = pathlib.Path("dist")
+        if dist_dir.exists():
+            shutil.rmtree(dist_dir)
+
+        shutil.copy2(setup_file, "setup.py")
+        try:
+            _run_python_checked(["-m", "build", "--wheel", "."], quiet=True)
+        finally:
+            _unlink_with_retry(pathlib.Path("setup.py"))
+
+        wheel_files = glob.glob("dist/*.whl")
+        assert len(wheel_files) == 1, f"Expected 1 wheel, found {wheel_files}"
         _run_python_checked(
             [
                 "-m",
                 "pip",
                 "install",
                 "--force-reinstall",
-                f"dist/{package_name}-{version_number}-{build_number}-py3-none-any.whl",
+                wheel_files[0],
                 "--quiet",
                 "--no-warn-script-location",
             ]
@@ -47,14 +50,32 @@ def main() -> None:
 
 
 def _run_python_checked(
-    args: typing.List[str], cwd: typing.Optional[pathlib.Path] = None
+    args: typing.List[str],
+    cwd: typing.Optional[pathlib.Path] = None,
+    quiet: bool = False,
 ) -> None:
     subprocess.run(
         [sys.executable, *args],
         check=True,
         cwd=cwd,
+        stdout=subprocess.DEVNULL if quiet else None,
+        stderr=subprocess.DEVNULL if quiet else None,
     )
 
 
+def _unlink_with_retry(
+    path: pathlib.Path, retries: int = 5, delay: float = 1.0
+) -> None:
+    for attempt in range(retries):
+        try:
+            path.unlink(missing_ok=True)
+            return
+        except PermissionError:
+            if attempt < retries - 1:
+                time.sleep(delay)
+            else:
+                raise
+
+
 if __name__ == "__main__":
     main()
diff --git a/tidy_code.sh b/tidy_code.sh
index b040afdf..aba3c914 100755
--- a/tidy_code.sh
+++ b/tidy_code.sh
@@ -2,3 +2,4 @@
 set -euo pipefail
 
 mise task --quiet run tidy_code
+git add --renormalize .