diff --git a/setup.py b/setup.py
index fc02be3..611a5f5 100644
--- a/setup.py
+++ b/setup.py
@@ -20,11 +20,19 @@ setup(
     classifiers=[
         'Development Status :: 1 - Planning',
         'License :: OSI Approved :: CEA CNRS Inria Logiciel Libre License, version 2.1 (CeCILL-2.1)',
+        'Programming Language :: Python :: 3.3',
+        'Programming Language :: Python :: 3.4',
+        'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3 :: Only',
+        'Programming Language :: Python :: Implementation :: CPython',
+        'Programming Language :: Python :: Implementation :: PyPy',
         'Topic :: Security',
     ],
     keywords='authentication password oath hotp totp',
     packages=find_packages(exclude=['contrib', 'docs', 'tests']),
+    python_requires='~=3.3',
     data_files=[
         ('license', ['LICENSE-EN.txt', 'LICENSE-FR.txt']),
     ],