diff --git a/.bumpversion.cfg b/.bumpversion.cfg
deleted file mode 100644
index 463404f..0000000
--- a/.bumpversion.cfg
+++ /dev/null
@@ -1,13 +0,0 @@
-[bumpversion]
-current_version = 18.0.4
-commit = True
-tag = True
-tag_name = {new_version}
-
-[bumpversion:file:oktacli/cli.py]
-search = VERSION = "{current_version}"
-replace = VERSION = "{new_version}"
-
-[bumpversion:file:setup.py]
-search = VERSION = "{current_version}"
-replace = VERSION = "{new_version}"
diff --git a/Makefile b/Makefile
index 30fd537..431caae 100644
--- a/Makefile
+++ b/Makefile
@@ -2,14 +2,38 @@ SHELL = bash
 
 all:    checkclean clean build
 
+
+_bump:
+	bump-my-version bump $(BUMP_WHAT)
+.PHONY: _bump
+
+
+_checkclean:
+	echo -e "\nCHECK IF BUILD DIR IS CLEAN ...\n"
+	git diff-index --quiet HEAD --
+.PHONY: _checkclean
+.SILENT: _checkclean
+
+
+_print_upload_message:
+	@echo -e "\nDONE.\nNow push & upload by executing ...\n"
+	@echo -e "    make upload\n\nHave fun :)"
+.PHONY: _print_upload_message
+
+
+%.txt: %.in
+	pip-compile -q --output-file "$@" "$<"
+
+requirements-dev.txt: requirements.txt
+
+requirements: requirements.txt requirements-dev.txt
+.PHONY: requirements
+
+
 test:
 	pytest
 .PHONY: test
 
-.PHONY: checkclean
-checkclean:
-	echo -e "\nCHECK IF BUILD DIR IS CLEAN ...\n"
-	git diff-index --quiet HEAD --
 
 .PHONY: clean
 clean:
@@ -20,52 +44,36 @@ clean:
 	rm -rf ignoreme build dist
 	rm -rf tmp
 
+
 .PHONY: build
 build: clean test
-	rm -rf build/ dist/
-	python setup.py sdist
-	python setup.py bdist_wheel
+	python -m build --wheel
+
 
 .PHONY: push
 push:
 	git push
 	git push --tags
 
+
 .PHONY: upload
 upload: push
 	twine upload dist/*
 
-.PHONY: now-upload-message
-now-upload-message:
-	@echo -e "\nDONE.\nNow push & upload by executing ...\n"
-	@echo -e "    make upload\n\nHave fun :)"
 
 # now let's get to the ones we use most often :)
 
-.PHONY: bump_major
-bump_major:
-	bumpversion major
-
-.PHONY: bump_minor
-bump_minor:
-	bumpversion minor
-
-.PHONY: bump_patch
-bump_patch:
-	bumpversion patch
 
+major: BUMP_WHAT := major
+major: _checkclean _bump build _print_upload_message
 .PHONY: major
-major: checkclean bump_major build now-upload-message
 
+
+minor: BUMP_WHAT := minor
+minor: _checkclean _bump build _print_upload_message
 .PHONY: minor
-minor: checkclean bump_minor build now-upload-message
 
-.PHONY: patch
-patch: checkclean bump_patch build now-upload-message
 
-dockertest:
-	@IMG="temp/$$(basename $$(pwd)):$$(date +%s)" ; \
-	echo $$IMG ; \
-	docker build . --no-cache --tag $$IMG ; \
-	docker run $$IMG
-.PHONY: test
+patch: BUMP_WHAT := patch
+patch: _checkclean _bump build _print_upload_message
+.PHONY: patch
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 0000000..5568187
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,70 @@
+# https://packaging.python.org/en/latest/specifications/declaring-project-metadata/
+
+
+[project]
+name = "okta-cli"
+authors = [{ name = "Axel Bock", email = "ab@a3b3.de" }]
+version = "18.0.4"
+requires-python = ">=3.7"
+
+description = "An Okta command line interface for scripting and quickly performing routine tasks"
+readme = "README.md"
+license = { text = "MIT License" }
+keywords = ["okta", "cli"]
+classifiers = [
+    # Trove classifiers
+    # Full list: https://pypi.python.org/pypi?%3Aaction=list_classifiers
+    "License :: OSI Approved :: MIT License",
+    "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 :: Implementation :: CPython",
+]
+
+dynamic = ["dependencies"]
+
+
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
+
+[tool.setuptools.dynamic.dependencies]
+file = "requirements.txt"
+
+
+[tool.setuptools.dynamic.optional-dependencies]
+dev = {file = "requirements-dev.txt"}
+
+
+[project.urls]
+Homepage = "https://github.com/flypenguin/okta-cli"
+Repository = "https://github.com/flypenguin/okta-cli"
+
+
+[project.scripts]
+okta-cli = "oktacli:cli_main"
+
+
+[tool.bumpversion]
+current_version = "18.0.4"
+commit = true
+tag = true
+message = "build(release): {current_version} -> {new_version}"
+tag_message = ""
+no_sign_tags = true
+
+
+[[tool.bumpversion.files]]
+filename = "oktacli/cli.py"
+search = "{current_version}"
+replace = "{new_version}"
+
+
+[[tool.bumpversion.files]]
+filename = "pyproject.toml"
+search = "{current_version}"
+replace = "{new_version}"
diff --git a/requirements-dev.in b/requirements-dev.in
new file mode 100644
index 0000000..0b66535
--- /dev/null
+++ b/requirements-dev.in
@@ -0,0 +1,4 @@
+-c requirements.txt
+bump-my-version
+pytest
+responses
diff --git a/requirements-dev.txt b/requirements-dev.txt
new file mode 100644
index 0000000..88af595
--- /dev/null
+++ b/requirements-dev.txt
@@ -0,0 +1,83 @@
+#
+# This file is autogenerated by pip-compile with Python 3.10
+# by the following command:
+#
+#    pip-compile --output-file=requirements-dev.txt requirements-dev.in
+#
+annotated-types==0.6.0
+    # via pydantic
+bump-my-version==0.12.0
+    # via -r requirements-dev.in
+certifi==2023.7.22
+    # via
+    #   -c requirements.txt
+    #   requests
+charset-normalizer==3.3.2
+    # via
+    #   -c requirements.txt
+    #   requests
+click==8.1.7
+    # via
+    #   -c requirements.txt
+    #   bump-my-version
+    #   rich-click
+exceptiongroup==1.1.3
+    # via pytest
+idna==3.4
+    # via
+    #   -c requirements.txt
+    #   requests
+iniconfig==2.0.0
+    # via pytest
+markdown-it-py==3.0.0
+    # via rich
+mdurl==0.1.2
+    # via markdown-it-py
+packaging==23.2
+    # via pytest
+pluggy==1.3.0
+    # via pytest
+pydantic==2.4.2
+    # via
+    #   bump-my-version
+    #   pydantic-settings
+pydantic-core==2.10.1
+    # via pydantic
+pydantic-settings==2.0.3
+    # via bump-my-version
+pygments==2.16.1
+    # via rich
+pytest==7.4.3
+    # via -r requirements-dev.in
+python-dotenv==1.0.0
+    # via pydantic-settings
+pyyaml==6.0.1
+    # via
+    #   -c requirements.txt
+    #   responses
+requests==2.31.0
+    # via
+    #   -c requirements.txt
+    #   responses
+responses==0.24.0
+    # via -r requirements-dev.in
+rich==13.6.0
+    # via
+    #   bump-my-version
+    #   rich-click
+rich-click==1.7.1
+    # via bump-my-version
+tomli==2.0.1
+    # via pytest
+tomlkit==0.12.2
+    # via bump-my-version
+typing-extensions==4.8.0
+    # via
+    #   pydantic
+    #   pydantic-core
+    #   rich-click
+urllib3==2.0.7
+    # via
+    #   -c requirements.txt
+    #   requests
+    #   responses
diff --git a/requirements.dev.txt b/requirements.dev.txt
deleted file mode 100644
index aefbcb6..0000000
--- a/requirements.dev.txt
+++ /dev/null
@@ -1 +0,0 @@
--e .[dev]
diff --git a/requirements.in b/requirements.in
new file mode 100644
index 0000000..b319f35
--- /dev/null
+++ b/requirements.in
@@ -0,0 +1,7 @@
+appdirs
+click
+requests
+openpyxl
+pony
+pyyaml
+six
diff --git a/requirements.txt b/requirements.txt
index d6e1198..8666e11 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,30 @@
--e .
+#
+# This file is autogenerated by pip-compile with Python 3.10
+# by the following command:
+#
+#    pip-compile --output-file=requirements.txt requirements.in
+#
+appdirs==1.4.4
+    # via -r requirements.in
+certifi==2023.7.22
+    # via requests
+charset-normalizer==3.3.2
+    # via requests
+click==8.1.7
+    # via -r requirements.in
+et-xmlfile==1.1.0
+    # via openpyxl
+idna==3.4
+    # via requests
+openpyxl==3.1.2
+    # via -r requirements.in
+pony==0.7.17
+    # via -r requirements.in
+pyyaml==6.0.1
+    # via -r requirements.in
+requests==2.31.0
+    # via -r requirements.in
+six==1.16.0
+    # via -r requirements.in
+urllib3==2.0.7
+    # via requests
diff --git a/setup.py b/setup.py
deleted file mode 100644
index f28fcab..0000000
--- a/setup.py
+++ /dev/null
@@ -1,145 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-
-# Note: Taken from here: https://github.com/kennethreitz/setup.py
-
-# Note: To use the 'upload' functionality of this file, you must:
-#   $ pip install twine
-
-import io
-import os
-import sys
-from shutil import rmtree
-
-from setuptools import find_packages, setup, Command
-
-# Package meta-data.
-VERSION = "18.0.4"
-
-NAME = "okta-cli"
-DESCRIPTION = (
-    "An Okta command line interface for scripting and quickly performing routine tasks"
-)
-URL = "https://github.com/flypenguin/okta-cli"
-EMAIL = "ab@a3b3.de"
-AUTHOR = "Axel Bock"
-REQUIRES_PYTHON = ">=3.7.0, <3.11"
-
-REQUIRED = [
-    "appdirs",
-    "click",
-    "requests",
-    "openpyxl",
-    "pony",
-    "pyyaml",
-    "six",  # dotted remainders ...
-]
-
-EXTRAS = [
-    "bumpversion",
-    "pre-commit",
-    "pytest",
-    "responses",
-    "tox",
-    "twine",
-    "wheel",
-]
-
-# The rest you shouldn't have to touch too much :)
-# ------------------------------------------------
-# Except, perhaps the License and Trove Classifiers!
-
-here = os.path.abspath(os.path.dirname(__file__))
-
-# Import the README and use it as the long-description.
-# Note: this will only work if 'README.md' is present in your MANIFEST.in file!
-try:
-    with io.open(os.path.join(here, "README.md"), encoding="utf-8") as f:
-        long_description = "\n" + f.read()
-except FileNotFoundError:
-    long_description = DESCRIPTION
-
-# Load the package's __version__.py module as a dictionary.
-about = {}
-if not VERSION:
-    with open(os.path.join(here, NAME, "__version__.py")) as f:
-        exec(f.read(), about)
-else:
-    about["__version__"] = VERSION
-
-
-class UploadCommand(Command):
-    """Support setup.py upload."""
-
-    description = "Build and publish the package."
-    user_options = []
-
-    @staticmethod
-    def status(s):
-        """Prints things in bold."""
-        print("\033[1m{0}\033[0m".format(s))
-
-    def initialize_options(self):
-        pass
-
-    def finalize_options(self):
-        pass
-
-    def run(self):
-        try:
-            self.status("Removing previous builds…")
-            rmtree(os.path.join(here, "dist"))
-        except OSError:
-            pass
-
-        self.status("Building Source and Wheel (universal) distribution…")
-        os.system("{0} setup.py sdist bdist_wheel --universal".format(sys.executable))
-
-        self.status("Uploading the package to PyPI via Twine…")
-        os.system("twine upload dist/*")
-
-        self.status("Pushing git tags ...")
-        os.system("git tag v{0}".format(about["__version__"]))
-        os.system("git push --tags")
-
-        sys.exit()
-
-
-# Where the magic happens:
-setup(
-    name=NAME,
-    version=about["__version__"],
-    description=DESCRIPTION,
-    long_description=long_description,
-    long_description_content_type="text/markdown",
-    author=AUTHOR,
-    author_email=EMAIL,
-    python_requires=REQUIRES_PYTHON,
-    url=URL,
-    packages=find_packages(exclude=("tests",)),
-    entry_points={
-        "console_scripts": ["okta-cli=oktacli:cli_main"],
-    },
-    install_requires=REQUIRED,
-    extras_require={
-        "dev": EXTRAS,
-    },
-    include_package_data=True,
-    license="MIT",
-    classifiers=[
-        # Trove classifiers
-        # Full list: https://pypi.python.org/pypi?%3Aaction=list_classifiers
-        "License :: OSI Approved :: MIT License",
-        "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 :: Implementation :: CPython",
-    ],
-    # $ setup.py publish support.
-    cmdclass={
-        "upload": UploadCommand,
-    },
-)