diff --git a/online-boutique-demo/src/recommendationservice/requirements.txt b/online-boutique-demo/src/recommendationservice/requirements.txt
index bc6c363..acc838d 100644
--- a/online-boutique-demo/src/recommendationservice/requirements.txt
+++ b/online-boutique-demo/src/recommendationservice/requirements.txt
@@ -25,7 +25,7 @@ opencensus-context==0.1.2  # via opencensus
 opencensus-ext-grpc==0.7.1  # via -r requirements.in
 opencensus-ext-stackdriver==0.7.3  # via -r requirements.in
 opencensus==0.7.11        # via -r requirements.in, opencensus-ext-grpc, opencensus-ext-stackdriver
-protobuf==3.13.0          # via google-api-core, googleapis-common-protos, grpcio-health-checking
+protobuf==6.33.5          # via google-api-core, googleapis-common-protos, grpcio-health-checking
 pyasn1-modules==0.2.8     # via google-auth
 pyasn1==0.4.8             # via pyasn1-modules, rsa
 python-json-logger==0.1.11  # via -r requirements.in