diff --git a/setup.py b/setup.py
index 95d4774..ee72cbc 100644
--- a/setup.py
+++ b/setup.py
@@ -86,7 +86,7 @@ setup_args = dict(
     extras_require   = {
         'test': ['ipykernel', 'ipython', 'mock'],
         'test:python_version == "3.3"': ['pytest<3.3.0'],
-        'test:python_version >= "3.4" or python_version == "2.7"': ['pytest'],
+        'test:(python_version >= "3.4" or python_version == "2.7")': ['pytest'],
     },
     cmdclass         = {
         'bdist_egg': bdist_egg if 'bdist_egg' in sys.argv else bdist_egg_disabled,