diff --git a/setup.cfg b/setup.cfg
index 34e37492..650fa648 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -13,6 +13,7 @@ classifier =
     License :: OSI Approved :: Apache Software License
     Operating System :: POSIX :: Linux
     Programming Language :: Python
+    Programming Language :: Python :: 3 :: Only
     Programming Language :: Python :: 3
     Programming Language :: Python :: 3.6
     Programming Language :: Python :: 3.7