diff --git a/.github/scripts/update-checker.sh b/.github/scripts/update-checker.sh
index 5169b09..2e8c912 100755
--- a/.github/scripts/update-checker.sh
+++ b/.github/scripts/update-checker.sh
@@ -249,6 +249,10 @@ check_tests_workflow() {
   if (( paths_ignore_count < 2 )); then
     actions+=("$tests_yml should contain at least 2 instances of 'paths-ignore:', found $paths_ignore_count, see upstream file $UPSTREAM/$tests_yml")
   fi
+  # Check for an 'os:' matrix, which makes it easy to add more runners, for example to test arm64
+  if ! grep -q "matrix.os" "$tests_yml"; then
+    actions+=("$tests_yml should use an 'os:' matrix and 'runs-on: \${{ matrix.os }}', see upstream file $UPSTREAM/$tests_yml")
+  fi
 }
 
 # Check docker-compose.*.yaml files for 'build:' with 'image:' usage
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index d3c308b..e86aa85 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -30,10 +30,11 @@ jobs:
   tests:
     strategy:
       matrix:
+        os: [ubuntu-latest, ubuntu-24.04-arm]
         ddev_version: [stable, HEAD]
       fail-fast: false
 
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
 
     steps:
       - uses: ddev/github-action-add-on-test@v2
diff --git a/README.md b/README.md
index 67ef2c2..d03a067 100644
--- a/README.md
+++ b/README.md
@@ -73,6 +73,7 @@ curl -fsSL https://ddev.com/s/addon-update-checker.sh | bash
 
    * In most cases, you only need to modify the `health_checks()` function and update the `GITHUB_REPO` variable to match your repository.
    * Tests will run automatically on every push to the repository, and periodically each night.
+   * Tests run on both AMD64 and ARM64 runners by default. You can add or remove runners in `matrix.os` in [.github/workflows/tests.yml](.github/workflows/tests.yml), see [GitHub-hosted runners](https://docs.github.com/en/actions/reference/runners/github-hosted-runners).
    * Please make sure to address test failures when they happen. Others will be depending on you.
    * Bats is a testing framework that just uses Bash. To run a Bats test locally, you have to install [bats-core](https://bats-core.readthedocs.io/en/stable/installation.html) and its [libraries](https://github.com/ztombol/bats-docs) first.
    * Then you download your add-on, and finally run `bats ./tests/test.bats` within the root of the uncompressed directory.