diff --git a/setup.py b/setup.py
index 82cae58bacbff35e7e147066b65f67ed5c1933f5..0e9be39066b78479af4f50d00f32b4c7ff132fa2 100755
--- a/setup.py
+++ b/setup.py
@@ -73,7 +73,7 @@ setup(
         'pysocks',
     ],
     extras_require={
-        'dev': [],
+        'dev': ['flake8'],
         'test': ['tox', 'pytest', 'pytest-cov'],
         # recommonmark: to make sphinx render markdown
         'doc': ['sphinx', 'recommonmark'],