diff --git a/setup.py b/setup.py
index 4eeb8d77..43082949 100644
--- a/setup.py
+++ b/setup.py
@@ -48,6 +48,7 @@ setup(
         "eth-utils>=0.7.4,<1.0.0",
     ],
     setup_requires=['setuptools-markdown'],
+    python_requires='>=3.5, <4',
     extras_require=extras_require,
     py_modules=['<MODULE_NAME>'],
     license="MIT",