diff --git a/setup.py b/setup.py
index 4b10e79..f5b7470 100755
--- a/setup.py
+++ b/setup.py
@@ -41,7 +41,13 @@ See http://propka.org/ for the PROPKA web server.
         'Environment :: Console',
         'Intended Audience :: Science/Research',
         'License :: OSI Approved :: GNU Lesser General Public License v2 (LGPLv2)',
-        'Operating System :: POSIX', 'Programming Language :: Python',
+        'Operating System :: POSIX', 
+        'Operating System :: MacOS :: MacOS X',
+        'Programming Language :: Python',
+        'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.8',
         'Topic :: Scientific/Engineering :: Bio-Informatics',
         'Topic :: Scientific/Engineering :: Chemistry',
         ],