diff --git a/pyproject.toml b/pyproject.toml
index eb227057565..c311f5d042c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -152,3 +152,7 @@ ignore-words-list = 'te,assertIn'
 # TODO(3.13): Remove aiohttp.helpers once https://github.com/python/cpython/pull/106771
 # is available in all supported cpython versions
 exclude-modules = "(^aiohttp\\.helpers)"
+
+[tool.black]
+# TODO: Remove target-version and reformat code
+target-version = ["py35"]