diff --git a/IPython/core/release.py b/IPython/core/release.py
index 50e0207..cb70d77 100644
--- a/IPython/core/release.py
+++ b/IPython/core/release.py
@@ -114,5 +114,6 @@ classifiers = [
     'License :: OSI Approved :: BSD License',
     'Programming Language :: Python',
     'Programming Language :: Python :: 3',
+    'Programming Language :: Python :: 3 :: Only',
     'Topic :: System :: Shells'
     ]