diff --git a/samples/hello_happybase/requirements.txt b/samples/hello_happybase/requirements.txt
index a144f03e1..d3368cd0f 100644
--- a/samples/hello_happybase/requirements.txt
+++ b/samples/hello_happybase/requirements.txt
@@ -1 +1,2 @@
 google-cloud-happybase==0.33.0
+six==1.16.0 # See https://github.com/googleapis/google-cloud-python-happybase/issues/128