diff --git a/packages/browsers/test/src/versions.ts b/packages/browsers/test/src/versions.ts
index 311b960a..3167a244 100644
--- a/packages/browsers/test/src/versions.ts
+++ b/packages/browsers/test/src/versions.ts
@@ -16,8 +16,6 @@
 
 export const testChromeBuildId = '113.0.5672.0';
 export const testChromiumBuildId = '1083080';
-// TODO: We can add a Cron job to auto-update on change.
-// Firefox keeps only `latest` version of Nightly builds.
 export const testFirefoxBuildId = '118.0a1';
 export const testChromeDriverBuildId = '115.0.5763.0';
 export const testChromeHeadlessShellBuildId = '118.0.5950.0';
diff --git a/packages/browsers/tools/updateVersions.mjs b/packages/browsers/tools/updateVersions.mjs
new file mode 100644
index 00000000..974358df
--- /dev/null
+++ b/packages/browsers/tools/updateVersions.mjs
@@ -0,0 +1,43 @@
+/**
+ * Copyright 2023 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import fs from 'node:fs/promises';
+
+const filePath = './test/src/versions.ts';
+
+const getVersion = async () => {
+  // https://stackoverflow.com/a/1732454/96656
+  const response = await fetch(
+    'https://archive.mozilla.org/pub/firefox/nightly/latest-mozilla-central/'
+  );
+  const html = await response.text();
+  const re = /firefox-(.*)\.en-US\.langpack\.xpi">/;
+  const match = re.exec(html)[1];
+  return match;
+};
+
+const patch = (input, version) => {
+  const output = input.replace(/testFirefoxBuildId = '([^']+)';/, match => {
+    return `testFirefoxBuildId = '${version}';`;
+  });
+  return output;
+};
+
+const version = await getVersion();
+
+const contents = await fs.readFile(filePath, 'utf8');
+const patched = patch(contents, version);
+fs.writeFile(filePath, patched);