diff --git a/test_requirements.txt b/test_requirements.txt
index b395a12..71875ba 100644
--- a/test_requirements.txt
+++ b/test_requirements.txt
@@ -1,6 +1,6 @@
 # Requirements to run unit tests. Tests import from
 # generated code.
-protobuf==4.21.9
+protobuf==4.21.12
 pytest==7.2.1
 grpc-stubs==1.24.12
 grpcio-tools==1.51.1