diff --git a/setup.cfg b/setup.cfg
index 6d7fc546..86536dc0 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -20,6 +20,7 @@ classifier =
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3.9
     Topic :: Internet :: Name Service (DNS)
 
 [files]