diff --git a/noxfile.py b/noxfile.py
index d75361f..bcea1fb 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -19,6 +19,7 @@
     "freezegun",
     "mock",
     "oauth2client",
+    "pyopenssl",
     "pytest",
     "pytest-cov",
     "pytest-localserver",