diff --git a/setup.py b/setup.py
index d906564e..11002a93 100644
--- a/setup.py
+++ b/setup.py
@@ -9,10 +9,7 @@ except ImportError:
 setup(
     name='cibuildwheel',
     version='0.9.4',
-    install_requires=[
-        'bashlex',
-        'monotonic',
-    ],
+    install_requires=['bashlex'],
     description="Build Python wheels on CI with minimal configuration.",
     long_description='For readme please see http://github.com/joerick/cibuildwheel',
     author="Joe Rickerby",