diff --git a/setup.py b/setup.py
index 0df0a81..055fcab 100644
--- a/setup.py
+++ b/setup.py
@@ -29,7 +29,10 @@
     "six>=1.9.0",
 )
 
-extras = {"aiohttp": "aiohttp >= 3.6.2, < 4.0.0dev; python_version>='3.6'"}
+extras = {
+    "aiohttp": "aiohttp >= 3.6.2, < 4.0.0dev; python_version>='3.6'",
+    "pyopenssl": "pyopenssl>=20.0.0",
+}
 
 with io.open("README.rst", "r") as fh:
     long_description = fh.read()