diff --git a/pyproject.toml b/pyproject.toml
index c6cd44a..8c4c866 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,6 +28,7 @@ classifiers = [
     "Operating System :: OS Independent",
     "Programming Language :: Python :: 3"
 ]
+requires-python = ">= 3.9"
 dependencies = [
     "azure-identity>=1.8.0",
     "azure-monitor-ingestion>=1.0.0",