diff --git a/.cloud-build/requirements.txt b/.cloud-build/requirements.txt
index 9346077c2..2ba09cc99 100644
--- a/.cloud-build/requirements.txt
+++ b/.cloud-build/requirements.txt
@@ -10,3 +10,4 @@ google-cloud-aiplatform
 google-cloud-storage
 google-cloud-build
 ratemate
+protobuf