diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 181f44b..06b94b0 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -79,6 +79,9 @@ jobs:
           - image: alpine:3.20
             dockerfile: Dockerfile.alpine
             platforms: linux/amd64,linux/arm64/v8
+          - image: alpine:3.21
+            dockerfile: Dockerfile.alpine
+            platforms: linux/amd64,linux/arm64/v8
     env:
       BASE_IMAGE: ${{ matrix.image }}
       DOCKER_DEPLOY_IMAGES: false
diff --git a/README.md b/README.md
index 4faa414..5c4e8d3 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ Images are available on:
 ```console
 ❯ docker build . -f Dockerfile.debian -t systemd-debian-sid  --build-arg base_image=debian:sid-slim
 ❯ docker build . -f Dockerfile.redhat -t systemd-almalinux-8  --build-arg base_image=almalinux:8
-❯ docker build . -f Dockerfile.alpine -t openrc-alpine3.18  --build-arg base_image=alpine:3.18
+❯ docker build . -f Dockerfile.alpine -t openrc-alpine3.20  --build-arg base_image=alpine:3.20
 ```
 
 Example `base_system` arguments :
@@ -36,6 +36,7 @@ Example `base_system` arguments :
 - `alpine:3.18`
 - `alpine:3.19`
 - `alpine:3.20`
+- `alpine:3.21`
 
 You can also use "non-slim" Debian images (`debian:11`) but we only build images
 based on `-slim` versions of Debian images.
@@ -60,6 +61,7 @@ The following containers are available from [Docker Hub](https://hub.docker.com/
 ❯ docker pull ghcr.io/fauust/docker-systemd:alpine-3.18
 ❯ docker pull ghcr.io/fauust/docker-systemd:alpine-3.19
 ❯ docker pull ghcr.io/fauust/docker-systemd:alpine-3.20
+❯ docker pull ghcr.io/fauust/docker-systemd:alpine-3.21
 ```
 
 ## Usage (docker)