diff --git a/setup.py b/setup.py
index 10e39f4..82ad5ba 100644
--- a/setup.py
+++ b/setup.py
@@ -63,4 +63,5 @@ def read(*rnames):
     include_package_data=True,
     zip_safe=False,
     install_requires=["defusedxml>=0.4.1", "Django>=4.2", "pysaml2>=6.5.1"],
+    python_requires=">=3.9",
 )