diff --git a/pyproject.toml b/pyproject.toml
index 2858e7d..c31a5de 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -22,6 +22,8 @@ ruff = "^0.6.4"  # ruff GitHub action handles install
 
 [tool.ruff]
 target-version = "py38"  # ruff doesn't yet infer this from [tool.poetry.dependencies]
+exclude = ["."]
+include = ["spond/*.py", "tests/*.py"]
 
 [tool.ruff.lint]
 # Enable only isort rules