diff --git a/docs/CONTRIBUTORS.rst b/docs/CONTRIBUTORS.rst
index 302c8c205b..bf68594158 100644
--- a/docs/CONTRIBUTORS.rst
+++ b/docs/CONTRIBUTORS.rst
@@ -114,7 +114,7 @@ Auto-formatting can be done on the command line:
 ::
 
     $ # TODO: configure black and isort args in pyproject.toml (see #1161)
-    $ black --line-length 80 tuf/api
+    $ black <filename>
     $ isort --line-length 80 --profile black -p tuf tuf/api
 
 or via source code editor plugin
diff --git a/pyproject.toml b/pyproject.toml
index 245e2cdf5f..be5e723804 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,7 +1,13 @@
+# Build-system section
 [build-system]
 requires = ["setuptools>=40.8.0", "wheel"]
 build-backend = "setuptools.build_meta"
 
+# Black section
+# Read more here: https://black.readthedocs.io/en/stable/usage_and_configuration/the_basics.html#configuration-via-a-file
+[tool.black]
+line-length=80
+
 # Pylint section
 
 # Minimal pylint configuration file for Secure Systems Lab Python Style Guide:
diff --git a/tox.ini b/tox.ini
index 767b1b4a86..b06150ea57 100644
--- a/tox.ini
+++ b/tox.ini
@@ -41,7 +41,7 @@ changedir = {toxinidir}
 commands =
     # Use different configs for new (tuf/api/*) and legacy code
     # TODO: configure black and isort args in pyproject.toml (see #1161)
-    black --check --diff --line-length 80 tuf/api tuf/ngclient
+    black --check --diff tuf/api tuf/ngclient
     isort --check --diff --line-length 80 --profile black -p tuf tuf/api tuf/ngclient
     pylint -j 0 tuf/api tuf/ngclient --rcfile=pyproject.toml