diff --git a/requirements.txt b/requirements.txt
index 96fbc33d64..cc927fdc2f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@ google-api-core==2.1.1
 googleapis-common-protos==1.53.0
 jinja2==3.0.2
 MarkupSafe==2.0.1
-protobuf==3.19.0
+protobuf==3.19.1
 pypandoc==1.6.4
 PyYAML==6.0
 dataclasses==0.6  # TODO(busunkim) remove when 3.6 support is dropped