diff --git a/setup.py b/setup.py
index c11f983..a19490a 100644
--- a/setup.py
+++ b/setup.py
@@ -29,7 +29,9 @@ setup(name=name,
 
       packages=['websockify'],
       include_package_data=True,
-      install_requires=['numpy'],
+      extras_require = {
+          'fastHyBi': ['numpy']
+      },
       zip_safe=False,
       entry_points={
         'console_scripts': [