diff --git a/CHANGELOG.md b/CHANGELOG.md
index a38e8be..31cd3c9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ## HEAD
 
+- Set `init.defaultBranch` in ci:setup to suppress `git init` warning in Git 2.30+ (https://github.com/heroku/hatchet/issues/172)
 - Switch `heroku ci:install_heroku` to the Heroku CLI standalone installer rather than the APT install method (https://github.com/heroku/hatchet/issues/171)
 
 ## 7.3.3
diff --git a/etc/ci_setup.rb b/etc/ci_setup.rb
index 4c016c7..335fbd0 100755
--- a/etc/ci_setup.rb
+++ b/etc/ci_setup.rb
@@ -30,6 +30,8 @@ def run_cmd(command)
 run_cmd "bundle exec hatchet install"
 run_cmd "git config --get user.email > /dev/null || git config --global user.email #{ENV.fetch('HEROKU_API_USER').shellescape}"
 run_cmd "git config --get user.name > /dev/null || git config --global user.name 'BuildpackTester'"
+# Suppress the `git init` warning in Git 2.30+ when no default branch name is set.
+run_cmd "git config --global init.defaultBranch main"
 
 puts "== Done =="