diff --git a/setup.py b/setup.py
index e2013f3fc..78b3ebc5e 100644
--- a/setup.py
+++ b/setup.py
@@ -101,7 +101,7 @@ def main():
         python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
         install_requires=install_requires,
         extras_require=extras_require,
-        packages=['_pytest', '_pytest.assertion', '_pytest._code'],
+        packages=['_pytest', '_pytest.assertion', '_pytest._code', '_pytest.mark'],
         py_modules=['pytest'],
         zip_safe=False,
     )