diff --git a/.github/workflows/tox.yml b/.github/workflows/tox.yml
index e003ff90..57ccd03a 100644
--- a/.github/workflows/tox.yml
+++ b/.github/workflows/tox.yml
@@ -66,6 +66,9 @@ jobs:
       - name: Install Node dependencies
         run: |
           npm install -g markdownlint-cli jshint csslint
+      - name: Check with black
+        if: always()
+        run: python -m tox -e black && git diff --exit-code
       - name: Check with flake8
         if: always()
         run: python -m tox -e flake8
diff --git a/requirements/project-min.txt b/requirements/project-min.txt
index 00719753..7dc9825c 100644
--- a/requirements/project-min.txt
+++ b/requirements/project-min.txt
@@ -1,5 +1,5 @@
 babel==2.9.0
-click==3.3
+click==8.0
 Jinja2==2.10.2
 markupsafe<=2.0.1
 Markdown==3.3
diff --git a/requirements/project.txt b/requirements/project.txt
index 2e1be0c8..bcf8e8d3 100644
--- a/requirements/project.txt
+++ b/requirements/project.txt
@@ -1,5 +1,5 @@
 babel>=2.9.0
-click>=7.0
+click>=8.0
 Jinja2>=2.10.2
 Markdown>=3.3,<3.4
 PyYAML>=5.2
diff --git a/requirements/test.txt b/requirements/test.txt
index 9c4e8691..d38598f9 100644
--- a/requirements/test.txt
+++ b/requirements/test.txt
@@ -1,2 +1,3 @@
 coverage
+black
 flake8
diff --git a/setup.cfg b/setup.cfg
index 1e6ff981..41194d3a 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,10 @@
 [metadata]
 license_file = LICENSE
 
+[flake8]
+max-line-length = 119
+extend-ignore = E203
+
 [compile_catalog]
 statistics = True
 domain = messages
diff --git a/tox.ini b/tox.ini
index e36af039..62799a82 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,7 @@
 [tox]
 envlist =
     py{36,37,38,39,310,py3}-{unittests,min-req,integration,integration-no-babel},
-    flake8, markdown-lint, linkchecker, jshint, csslint, nobabel, codespell
+    black, flake8, markdown-lint, linkchecker, jshint, csslint, nobabel, codespell
 
 [testenv]
 passenv = LANG
@@ -16,9 +16,13 @@ commands=
     py{36,37,38,39,310,py3}-unittests: {envbindir}/coverage report --show-missing
     py{36,37,38,39,310,py3}-integration: {envpython} -m mkdocs.tests.integration --output={envtmpdir}/builds
 
+[testenv:black]
+deps=-rrequirements/test.txt
+commands={envbindir}/black -l100 -tpy36 --skip-string-normalization mkdocs
+
 [testenv:flake8]
 deps=-rrequirements/test.txt
-commands={envbindir}/flake8 mkdocs --max-line-length=119
+commands={envbindir}/flake8 mkdocs
 
 [testenv:markdown-lint]
 whitelist_externals=