diff --git a/Dockerfile b/Dockerfile
index 7e57e96..dba2525 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-#syntax=docker/dockerfile:1.1-experimental
+#syntax=docker/dockerfile:1.2
 
 FROM node:14 AS deps
 WORKDIR /src
diff --git a/README.md b/README.md
index 06a2f24..8372c86 100644
--- a/README.md
+++ b/README.md
@@ -8,6 +8,11 @@
 
 GitHub Action to set up Docker [Buildx](https://github.com/docker/buildx).
 
+This action will create and boot a builder that can be used in the following steps of your workflow if you're using
+[buildx](https://github.com/docker/buildx). By default, the `docker-container` [builder driver](https://github.com/docker/buildx#--driver-driver)
+will be used to be able to build multi-platform images and export cache thanks to the [BuildKit](https://github.com/moby/buildkit)
+container.
+
 > :bulb: See also:
 > * [login](https://github.com/docker/login-action) action
 > * [setup-qemu](https://github.com/docker/setup-qemu-action) action