diff --git a/packages/google-cloud-texttospeech/noxfile.py b/packages/google-cloud-texttospeech/noxfile.py
index cf5293f2819a..8b525ab05f4d 100644
--- a/packages/google-cloud-texttospeech/noxfile.py
+++ b/packages/google-cloud-texttospeech/noxfile.py
@@ -110,8 +110,7 @@ def system(session):
 
     # Install all test dependencies, then install this package into the
     # virtualenv's dist-packages.
-    session.install("mock", "pytest")
-    session.install("git+https://github.com/googleapis/python-test-utils")
+    session.install("mock", "pytest", "google-cloud-testutils")
     session.install("-e", ".")
 
     # Run py.test against the system tests.