diff --git a/pyproject.toml b/pyproject.toml
index 637db49..96a71b7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,7 +9,7 @@ author-email = "git@louie.lu"
 maintainer = "Louie Lu"
 maintainer-email = "git@louie.lu"
 home-page = "https://github.com/mlouielu/twstock"
-requires-python = ">=3"
+requires-python = ">=3.5"
 requires = [ "requests",]
 description-file = "README.md"
 classifiers = [ "License :: OSI Approved :: MIT License", "Programming Language :: Python :: 3",]