diff --git a/pyproject.toml b/pyproject.toml
index e7473d86..2891b2b4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -25,7 +25,7 @@ classifiers = [
     "Topic :: Software Development :: Libraries",
     "Topic :: Software Development :: Libraries :: Python Modules",
 ]
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 dependencies = [
     "requests>=2.28.2",
     "pystac[validation]>=1.10.0",