diff --git a/noxfile.py b/noxfile.py
index 438ff41..6523b32 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -43,6 +43,7 @@
     )
 
 
+@nox.session(python=["2.7", "3.5", "3.6", "3.7"])
 @nox.parametrize(
     "oauth2client",
     [
@@ -52,7 +53,6 @@
         "oauth2client>=4,<=5dev",
     ],
 )
-@nox.session(python=["2.7", "3.5", "3.6", "3.7"])
 def unit(session, oauth2client):
     session.install(*test_dependencies)
     session.install(oauth2client)