diff --git a/tests/flake8_project/pyproject.toml b/tests/flake8_project/pyproject.toml
index eb3a8418db02a20c20f9be1933c768c7576c65b0..9287d46cde9195bdaea03e32b40eccf39304505c 100644
--- a/tests/flake8_project/pyproject.toml
+++ b/tests/flake8_project/pyproject.toml
@@ -9,3 +9,8 @@ authors = [
     { name = "Author Name", email = "author.name@example.com" },
 ]
 description = "A description of what the package is for."
+
+[project.optional-dependencies]
+CODE_QUALITY = [
+    "flake8",
+]