diff --git a/pyproject.toml b/pyproject.toml
index e50cf13..4b1b6ad 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -128,6 +128,9 @@ markers = [
     "smoke: end-to-end smoke tests requiring the assembled FAST-HEP environment",
 ]
 
+[tool.mypy]
+python_version = "3.12"
+
 [[tool.mypy.overrides]]
 module = [
     "pyarrow",