diff --git a/setup.cfg b/setup.cfg
index b54ff289e..125675e75 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -16,6 +16,7 @@ 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