diff --git a/setup.cfg b/setup.cfg
index a370b94b6..7fd36eaf2 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -19,6 +19,7 @@ classifiers =
     Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
     Topic :: Internet :: Name Service (DNS)