diff --git a/py/pyproject.toml b/py/pyproject.toml
index 2637976..9d5691f 100644
--- a/py/pyproject.toml
+++ b/py/pyproject.toml
@@ -8,7 +8,7 @@ dynamic = ["version"]
 authors = [{name = "Milan Skocic", email = "milan.skocic@icloud.com"}]
 description = "pycodata: CODATA constants for python."
 readme = "README.md"
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 license = {text = "License :: OSI Approved :: MIT License"}
 classifiers=["Development Status :: 5 - Production/Stable",
              "Intended Audience :: Science/Research",