diff --git a/DEVELOPING.md b/DEVELOPING.md
index 557eaa5ec09e59a1b02e4c27d7ec15ec697a8ea4..13980971a650957ad507c6bcd1fbbb7c106acd4c 100644
--- a/DEVELOPING.md
+++ b/DEVELOPING.md
@@ -7,7 +7,7 @@ A simple setup is enough for most users to start contributing to Automatic Updat
 Assuming you meet the [system requirements](#system-requirements), simply run the following command <sup>[[1]](#footnote-1), [[2]](#footnote-2)</sup> from the directory you would like to install your development environment under <sup>[[3]](#footnote-3)</sup>. It will prompt for confirmation before beginning.
 
 ```shell
-/bin/bash -c "$(curl -fsSL https://git.drupalcode.org/project/automatic_updates/-/raw/8.x-2.x/scripts/setup_local_dev.sh)"
+/bin/bash -c "$(curl -fsSL https://git.drupalcode.org/project/automatic_updates/-/raw/3.0.x/scripts/setup_local_dev.sh)"
 ```
 
 That's it. The success message will display next steps.
@@ -41,7 +41,7 @@ Several details of your setup can be customized via environment variables. Set t
 ```shell
 DRUPAL_CORE_BRANCH="10.0.x" # The branch of Drupal core that will be installed.
 DRUPAL_CORE_SHALLOW_CLONE="TRUE" # Whether or not to do a "shallow clone" of Drupal core. (Defaults to TRUE.) See note below.
-AUTOMATIC_UPDATES_BRANCH="8.x-2.x" # The branch of the Automatic Updates module that will be installed.
+AUTOMATIC_UPDATES_BRANCH="3.0.x" # The branch of the Automatic Updates module that will be installed.
 SITE_DIRECTORY="auto_updates_dev" # The path to the directory where the dev environment will be installed.
 SITE_HOST=".test" # The path for Drupal's TRUSTED_HOST_PATTERN.
 ```
@@ -59,7 +59,7 @@ git fetch --unshallow
 You can download the setup script first to review its contents or modify it before running it:
 
 ```shell
-curl --output setup_local_dev.sh https://git.drupalcode.org/project/automatic_updates/-/raw/8.x-2.x/scripts/setup_local_dev.sh
+curl --output setup_local_dev.sh https://git.drupalcode.org/project/automatic_updates/-/raw/3.0.x/scripts/setup_local_dev.sh
 
 ./scripts/setup_local_dev.sh
 ```
@@ -82,7 +82,7 @@ To set up your environment manually, use the setup script as a reference.
 
 ---
 
-<a name="footnote-1"><sup>1</sup></a> When running a script downloaded from the Web, it is always wise to read its contents first. Ours ([`setup_local_dev.sh`](https://git.drupalcode.org/project/automatic_updates/-/raw/8.x-2.x/scripts/setup_local_dev.sh)) is documented with code comments to help with that. For a more cautious approach, see [Alternative setup options](#alternative-setup-options) above.
+<a name="footnote-1"><sup>1</sup></a> When running a script downloaded from the Web, it is always wise to read its contents first. Ours ([`setup_local_dev.sh`](https://git.drupalcode.org/project/automatic_updates/-/raw/3.0.x/scripts/setup_local_dev.sh)) is documented with code comments to help with that. For a more cautious approach, see [Alternative setup options](#alternative-setup-options) above.
 
 <a name="footnote-2"><sup>2</sup></a> Curl options explained:
 [`-f, --fail`](https://curl.se/docs/manpage.html#-f),
diff --git a/scripts/setup_local_dev.sh b/scripts/setup_local_dev.sh
index e803de8e63ff59b7102780bc0ba8bc591d83ac05..e9e04b5a7e86b41ce2a074a6c7642c0cfde87cd1 100755
--- a/scripts/setup_local_dev.sh
+++ b/scripts/setup_local_dev.sh
@@ -26,7 +26,7 @@ safe_realpath() {
 # Variables beginning with an underscore (_) cannot be overridden.
 DRUPAL_CORE_BRANCH=${DRUPAL_CORE_BRANCH:="10.0.x"}
 DRUPAL_CORE_SHALLOW_CLONE=${DRUPAL_CORE_SHALLOW_CLONE:="TRUE"}
-AUTOMATIC_UPDATES_BRANCH=${AUTOMATIC_UPDATES_BRANCH:="8.x-2.x"}
+AUTOMATIC_UPDATES_BRANCH=${AUTOMATIC_UPDATES_BRANCH:="3.0.x"}
 SITE_DIRECTORY=${SITE_DIRECTORY:="auto_updates_dev"}
 _SITE_DIRECTORY_REALPATH=$(safe_realpath "$SITE_DIRECTORY")
 _SITE_DIRECTORY_BASENAME=$(basename "$_SITE_DIRECTORY_REALPATH")