diff --git a/google-cloud-speech/nox.py b/google-cloud-speech/nox.py
index 0f68f5c8f4eb..ef4f907a1b60 100644
--- a/google-cloud-speech/nox.py
+++ b/google-cloud-speech/nox.py
@@ -26,15 +26,15 @@
 
 
 @nox.session
-@nox.parametrize('python_version', ['2.7', '3.4', '3.5', '3.6'])
-def unit_tests(session, python_version):
+@nox.parametrize('py', ['2.7', '3.4', '3.5', '3.6'])
+def unit(session, py):
     """Run the unit test suite."""
 
     # Run unit tests against all supported versions of Python.
-    session.interpreter = 'python{}'.format(python_version)
+    session.interpreter = 'python{}'.format(py)
 
     # Set the virtualenv dirname.
-    session.virtualenv_dirname = 'unit-' + python_version
+    session.virtualenv_dirname = 'unit-' + py
 
     # Install all test dependencies, then install this package in-place.
     session.install('mock', 'pytest', 'pytest-cov', *LOCAL_DEPS)
@@ -55,8 +55,8 @@ def unit_tests(session, python_version):
 
 
 @nox.session
-@nox.parametrize('python_version', ['2.7', '3.6'])
-def system_tests(session, python_version):
+@nox.parametrize('py', ['2.7', '3.6'])
+def system(session, py):
     """Run the system test suite."""
 
     # Sanity check: Only run system tests if the environment variable is set.
@@ -64,10 +64,10 @@ def system_tests(session, python_version):
         session.skip('Credentials must be set via environment variable.')
 
     # Run the system tests against latest Python 2 and Python 3 only.
-    session.interpreter = 'python{}'.format(python_version)
+    session.interpreter = 'python{}'.format(py)
 
     # Set the virtualenv dirname.
-    session.virtualenv_dirname = 'sys-' + python_version
+    session.virtualenv_dirname = 'sys-' + py
 
     # Install all test dependencies, then install this package into the
     # virtualenv's dist-packages.