diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 7de3922..114d43b 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -33,5 +33,8 @@ jobs:
           pip3 --version
           pip3 install setuptools tox
 
-      - name: Run tox
+      - name: Run pytest
         run: tox -e py
+
+      - name: Run flake8
+        run: tox -e flake8
diff --git a/MANIFEST.in b/MANIFEST.in
index 243f0e5..c80189b 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,5 +1,4 @@
 include README.rst
 include LICENSE
-include requirements_dev.txt
 include tox.ini
 include Makefile
diff --git a/pyproject.toml b/pyproject.toml
index f4bac66..be506b2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,9 +23,15 @@ classifiers = [
 Homepage = "https://github.com/mivade/argparse_dataclass"
 
 [project.optional-dependencies]
-dev = ["black", "flake8", "tox", "pytest", "build"]
+dev = ["black", "flake8", "flake8-pyproject", "tox", "pytest", "build"]
 
 [build-system]
 requires = ["setuptools", "wheel"]
 build-backend = "setuptools.build_meta"
 
+[tool.flake8]
+# Recommended by black
+max-line-length = 88
+extend-ignore = [
+    "E501", # line too long, even for constants - incompatible with black
+]
diff --git a/requirements_dev.txt b/requirements_dev.txt
deleted file mode 100644
index 69b3e34..0000000
--- a/requirements_dev.txt
+++ /dev/null
@@ -1,5 +0,0 @@
-black
-flake8
-tox
-pytest
-build
diff --git a/tox.ini b/tox.ini
index 586e5cb..a417cf6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,11 +4,10 @@ envlist = py39, py310, py311, py312, py313
 # isolated_build = True
 
 [testenv]
-deps =
-    -r {toxinidir}/requirements_dev.txt
+extras = dev
 commands =
     python -m doctest argparse_dataclass.py
     pytest
-commands_post =
-    black --check argparse_dataclass.py
-    black --check tests
+
+[testenv:flake8]
+commands = flake8 {posargs}