diff --git a/packages/google-cloud-python-speech/synth.py b/packages/google-cloud-python-speech/synth.py
index ffc94a7ad780..d28372d6b3a5 100644
--- a/packages/google-cloud-python-speech/synth.py
+++ b/packages/google-cloud-python-speech/synth.py
@@ -60,3 +60,5 @@
 # ----------------------------------------------------------------------------
 templated_files = common.py_library(unit_cov_level=97, cov_level=100)
 s.move(templated_files)
+
+s.shell.run(["nox", "-s", "blacken"], hide_output=False)