diff --git a/.github/generated-files-bot.yml b/.github/generated-files-bot.yml
index 7bb7ce54..992ccef4 100644
--- a/.github/generated-files-bot.yml
+++ b/.github/generated-files-bot.yml
@@ -8,9 +8,9 @@ generatedFiles:
 - path: '.github/generated-files-bot.+(yml|yaml)'
   message: '`.github/generated-files-bot.(yml|yaml)` should be updated in [`synthtool`](https://github.com/googleapis/synthtool)'
 - path: 'README.md'
-  message: '`README.md` is managed by [`synthtool`](https://github.com/googleapis/synthtool). However, a partials file can be used to update the README, e.g.: https://github.com/googleapis/nodejs-storage/blob/master/.readme-partials.yaml'
+  message: '`README.md` is managed by [`synthtool`](https://github.com/googleapis/synthtool). However, a partials file can be used to update the README, e.g.: https://github.com/googleapis/nodejs-storage/blob/main/.readme-partials.yaml'
 - path: 'samples/README.md'
-  message: '`samples/README.md` is managed by [`synthtool`](https://github.com/googleapis/synthtool). However, a partials file can be used to update the README, e.g.: https://github.com/googleapis/nodejs-storage/blob/master/.readme-partials.yaml'
+  message: '`samples/README.md` is managed by [`synthtool`](https://github.com/googleapis/synthtool). However, a partials file can be used to update the README, e.g.: https://github.com/googleapis/nodejs-storage/blob/main/.readme-partials.yaml'
 ignoreAuthors:
 - 'gcf-owl-bot[bot]'
 - 'yoshi-automation'
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index f033c0d2..36dbfb21 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -1,7 +1,7 @@
 on:
   push:
     branches:
-      - master
+      - main
   pull_request:
 name: ci
 jobs:
diff --git a/README.md b/README.md
index 9dd765f6..106b54ef 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@
 
 [![release level](https://img.shields.io/badge/release%20level-general%20availability%20%28GA%29-brightgreen.svg?style=flat)](https://cloud.google.com/terms/launch-stages)
 [![npm version](https://img.shields.io/npm/v/@google-cloud/iot.svg)](https://www.npmjs.org/package/@google-cloud/iot)
-[![codecov](https://img.shields.io/codecov/c/github/googleapis/nodejs-iot/master.svg?style=flat)](https://codecov.io/gh/googleapis/nodejs-iot)
+[![codecov](https://img.shields.io/codecov/c/github/googleapis/nodejs-iot/main.svg?style=flat)](https://codecov.io/gh/googleapis/nodejs-iot)
 
 
 
@@ -17,7 +17,7 @@
 
 
 A comprehensive list of changes in each version may be found in
-[the CHANGELOG](https://github.com/googleapis/nodejs-iot/blob/master/CHANGELOG.md).
+[the CHANGELOG](https://github.com/googleapis/nodejs-iot/blob/main/CHANGELOG.md).
 
 * [Google Cloud Internet of Things (IoT) Core Node.js Client API Reference][client-docs]
 * [Google Cloud Internet of Things (IoT) Core Documentation][product-docs]
@@ -80,11 +80,11 @@ quickstart();
 
 ## Samples
 
-Samples are in the [`samples/`](https://github.com/googleapis/nodejs-iot/tree/master/samples) directory. Each sample's `README.md` has instructions for running its sample.
+Samples are in the [`samples/`](https://github.com/googleapis/nodejs-iot/tree/main/samples) directory. Each sample's `README.md` has instructions for running its sample.
 
 | Sample                      | Source Code                       | Try it |
 | --------------------------- | --------------------------------- | ------ |
-| Quickstart | [source code](https://github.com/googleapis/nodejs-iot/blob/master/samples/quickstart.js) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/nodejs-iot&page=editor&open_in_editor=samples/quickstart.js,samples/README.md) |
+| Quickstart | [source code](https://github.com/googleapis/nodejs-iot/blob/main/samples/quickstart.js) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/nodejs-iot&page=editor&open_in_editor=samples/quickstart.js,samples/README.md) |
 
 
 
@@ -133,7 +133,7 @@ More Information: [Google Cloud Platform Launch Stages][launch_stages]
 
 ## Contributing
 
-Contributions welcome! See the [Contributing Guide](https://github.com/googleapis/nodejs-iot/blob/master/CONTRIBUTING.md).
+Contributions welcome! See the [Contributing Guide](https://github.com/googleapis/nodejs-iot/blob/main/CONTRIBUTING.md).
 
 Please note that this `README.md`, the `samples/README.md`,
 and a variety of configuration files in this repository (including `.nycrc` and `tsconfig.json`)
@@ -145,7 +145,7 @@ to its templates in
 
 Apache Version 2.0
 
-See [LICENSE](https://github.com/googleapis/nodejs-iot/blob/master/LICENSE)
+See [LICENSE](https://github.com/googleapis/nodejs-iot/blob/main/LICENSE)
 
 [client-docs]: https://cloud.google.com/nodejs/docs/reference/iot/latest
 [product-docs]: https://cloud.google.com/iot
diff --git a/samples/README.md b/samples/README.md
index 30a621cb..00ce1e11 100644
--- a/samples/README.md
+++ b/samples/README.md
@@ -33,7 +33,7 @@ Before running the samples, make sure you've followed the steps outlined in
 
 ### Quickstart
 
-View the [source code](https://github.com/googleapis/nodejs-iot/blob/master/samples/quickstart.js).
+View the [source code](https://github.com/googleapis/nodejs-iot/blob/main/samples/quickstart.js).
 
 [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/nodejs-iot&page=editor&open_in_editor=samples/quickstart.js,samples/README.md)