diff --git a/CHANGELOG.md b/CHANGELOG.md
index 70b277120..d5981c755 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,13 @@
 
 [1]: https://www.npmjs.com/package/@google-cloud/pubsub?activeTab=versions
 
+## [3.7.3](https://github.com/googleapis/nodejs-pubsub/compare/v3.7.2...v3.7.3) (2023-07-26)
+
+
+### Bug Fixes
+
+* Update masks for topic should be snake case ([#1778](https://github.com/googleapis/nodejs-pubsub/issues/1778)) ([ba72638](https://github.com/googleapis/nodejs-pubsub/commit/ba7263836e6951454f77f631c9d2eb0a4df98da5))
+
 ## [3.7.2](https://github.com/googleapis/nodejs-pubsub/compare/v3.7.1...v3.7.2) (2023-07-24)
 
 
diff --git a/package.json b/package.json
index 1983860f8..9da69f11f 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@google-cloud/pubsub",
   "description": "Cloud Pub/Sub Client Library for Node.js",
-  "version": "3.7.2",
+  "version": "3.7.3",
   "license": "Apache-2.0",
   "author": "Google Inc.",
   "engines": {
diff --git a/protos/google/pubsub/v1/pubsub.proto b/protos/google/pubsub/v1/pubsub.proto
index 9ff80f2f6..4468de178 100644
--- a/protos/google/pubsub/v1/pubsub.proto
+++ b/protos/google/pubsub/v1/pubsub.proto
@@ -1030,7 +1030,11 @@ message CloudStorageConfig {
   // Message payloads and metadata will be written to files as an Avro binary.
   message AvroConfig {
     // When true, write the subscription name, message_id, publish_time,
-    // attributes, and ordering_key as additional fields in the output.
+    // attributes, and ordering_key as additional fields in the output. The
+    // subscription name, message_id, and publish_time fields are put in their
+    // own fields while all other message properties other than data (for
+    // example, an ordering_key, if present) are added as entries in the
+    // attributes map.
     bool write_metadata = 1;
   }
 
diff --git a/samples/package.json b/samples/package.json
index 17d22cc10..62c162c7b 100644
--- a/samples/package.json
+++ b/samples/package.json
@@ -21,7 +21,7 @@
     "precompile": "npm run clean"
   },
   "dependencies": {
-    "@google-cloud/pubsub": "^3.7.2",
+    "@google-cloud/pubsub": "^3.7.3",
     "@opentelemetry/api": "^1.0.0",
     "@opentelemetry/tracing": "^0.24.0",
     "avro-js": "^1.10.1",
diff --git a/src/topic.ts b/src/topic.ts
index 03a54c37c..96b33490e 100644
--- a/src/topic.ts
+++ b/src/topic.ts
@@ -48,6 +48,7 @@ import {
   SubscriptionOptions,
 } from './subscription';
 import {promisifySome} from './util';
+import snakeCase = require('lodash.snakecase');
 
 export type TopicMetadata = google.pubsub.v1.ITopic;
 
@@ -951,7 +952,7 @@ export class Topic {
     callback = typeof optsOrCallback === 'function' ? optsOrCallback : callback;
 
     const topic = Object.assign({name: this.name}, options);
-    const updateMask = {paths: Object.keys(options)};
+    const updateMask = {paths: Object.keys(options).map(snakeCase)};
     const reqOpts = {topic, updateMask};
 
     this.request<TopicMetadata>(
diff --git a/system-test/pubsub.ts b/system-test/pubsub.ts
index eab472ca8..4301292aa 100644
--- a/system-test/pubsub.ts
+++ b/system-test/pubsub.ts
@@ -307,6 +307,22 @@ describe('pubsub', () => {
       );
     });
 
+    it('should set metadata for a topic', async () => {
+      const threeDaysInSeconds = 3 * 24 * 60 * 60;
+
+      const topic = pubsub.topic(TOPIC_NAMES[0]);
+      await topic.setMetadata({
+        messageRetentionDuration: {
+          seconds: threeDaysInSeconds,
+        },
+      });
+      const [metadata] = await topic.getMetadata();
+      const {seconds, nanos} = metadata.messageRetentionDuration!;
+
+      assert.strictEqual(Number(seconds), threeDaysInSeconds);
+      assert.strictEqual(Number(nanos), 0);
+    });
+
     describe('ordered messages', () => {
       interface Expected {
         key: string;
diff --git a/test/topic.ts b/test/topic.ts
index bbd0aa2df..1179c718b 100644
--- a/test/topic.ts
+++ b/test/topic.ts
@@ -671,6 +671,7 @@ describe('Topic', () => {
   describe('setMetadata', () => {
     const METADATA = {
       labels: {yee: 'haw'},
+      messageRetentionDuration: {moo: 'cows'},
     };
 
     let requestStub: sinon.SinonStub;
@@ -691,7 +692,9 @@ describe('Topic', () => {
       topic.setMetadata(METADATA, assert.ifError);
 
       const expectedTopic = Object.assign({name: topic.name}, METADATA);
-      const expectedUpdateMask = {paths: ['labels']};
+      const expectedUpdateMask = {
+        paths: ['labels', 'message_retention_duration'],
+      };
 
       const [{reqOpts}] = requestStub.lastCall.args;
       assert.deepStrictEqual(reqOpts.topic, expectedTopic);