diff --git a/pom.xml b/pom.xml
index 646b92e3..4ecd6cda 100644
--- a/pom.xml
+++ b/pom.xml
@@ -63,7 +63,7 @@
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
     <github.global.server>github</github.global.server>
     <site.installationModule>google-iam-parent</site.installationModule>
-    <protobuf.version>3.21.8</protobuf.version>
+    <protobuf.version>3.21.9</protobuf.version>
     <junit.version>4.13.2</junit.version>
     <grpc.version>1.50.2</grpc.version>
     <guava.version>31.1-android</guava.version>