diff --git a/setup.py b/setup.py
index a66e39e..861e285 100644
--- a/setup.py
+++ b/setup.py
@@ -10,6 +10,7 @@ setup(
     package_dir={'': 'src'},
     install_requires=[
         "aiohttp==3.5.4",
-        "certifi==2019.3.9"
+        "certifi==2019.3.9",
+        "psutil==5.6.3; sys_platform == 'darwin'"
     ]
 )