--- a/setup.py	Fri Aug 09 12:48:58 2019 +0200
+++ b/setup.py	Wed Aug 07 15:21:17 2019 +0200
@@ -29,6 +29,8 @@
     'hgext3rd.topic',
 ]
 
+py_versions = '>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*, <4'
+
 if os.environ.get('INCLUDE_INHIBIT'):
     py_modules.append('hgext3rd.evolve.hack.inhibit')
     py_modules.append('hgext3rd.evolve.hack.directaccess')
@@ -46,5 +48,6 @@
     keywords='hg mercurial',
     license='GPLv2+',
     py_modules=py_modules,
-    packages=py_packages
+    packages=py_packages,
+    python_requires=py_versions
 )