diff --git a/.github/workflows/acceptance.yml b/.github/workflows/acceptance.yml
index 3687b2d..f6227ab 100644
--- a/.github/workflows/acceptance.yml
+++ b/.github/workflows/acceptance.yml
@@ -14,7 +14,7 @@ jobs:
   test:
     if: ${{ github.event_name == 'push' || github.event.label.name == 'run-acceptance-tests' || github.event_name == 'schedule' || github.event_name == 'workflow_dispatch' }}
     name: Acceptance
-    container: heroku/heroku:20-build
+    container: heroku/heroku:24-build
     runs-on: ubuntu-latest
     env:
       SLUGCMPLR_ACC: "true"
diff --git a/README.md b/README.md
index c217ff6..ec08887 100644
--- a/README.md
+++ b/README.md
@@ -56,7 +56,7 @@ The `CACHE-DIR` will be used by the buildpacks as their cache argument to speed
 up builds in the future, as per the [Buildpack API](https://devcenter.heroku.com/articles/buildpack-api)
 
 To guarantee full compatibility, it is recommended to run this step using
-Heroku's build containers. `heroku/heroku:20-build` or `heroku/heroku:18-build`.
+Heroku's build containers. e.g. `heroku/heroku:24-build`.
 
 #### `release --build-dir [BUILD-DIR]`