diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ae9b341e0..b82b462f5 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -27,7 +27,7 @@ jobs:
     - name: Install packages
       run: pip install tox
     - name: Run Tox
-      run: tox -e mypy,package_readme
+      run: tox -e lint,package_readme
 
   test:
     runs-on: ${{ matrix.platform }}
diff --git a/dev-requirements.txt b/dev-requirements.txt
index 73eae6803..a986a1fe7 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -3,3 +3,6 @@ tox>=2.5
 bump2version>=0.5.6
 sphinx>=1.5.5
 mypy>=0.782
+
+# Pin black as each version could change formatting, breaking CI randomly.
+black==22.12.0
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 000000000..5a8e741b0
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,2 @@
+[tool.black]
+target-version = ["py37"]
diff --git a/tox.ini b/tox.ini
index 0149f3092..3bdbbe703 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 minversion = 3.0
-envlist = mypy, py3{7,8,9,10,11}-cov, htmlcov
+envlist = lint, py3{7,8,9,10,11}-cov, htmlcov
 skip_missing_interpreters=true
 
 [testenv]
@@ -41,11 +41,12 @@ commands =
     coverage combine
     coverage html
 
-[testenv:mypy]
+[testenv:lint]
 deps =
     -r dev-requirements.txt
 skip_install = true
 commands =
+    black --check --diff .
     mypy
 
 [testenv:codecov]