diff --git a/packages/google-cloud-storage/testing/constraints-3.10.txt b/packages/google-cloud-storage/testing/constraints-3.10.txt
index 97296ecabb9a..0637ec419624 100644
--- a/packages/google-cloud-storage/testing/constraints-3.10.txt
+++ b/packages/google-cloud-storage/testing/constraints-3.10.txt
@@ -13,7 +13,7 @@ google-resumable-media==2.7.2
 grpcio==1.44.0
 grpcio-status==1.44.0
 proto-plus==1.22.3
-protobuf==4.25.8
+protobuf==5.29.6
 grpc-google-iam-v1==0.14.0
 opentelemetry-api==1.1.0
 requests==2.22.0