diff --git a/dockerimg/pushdockerimg.go b/dockerimg/pushdockerimg.go
index cd9e543..41d1b65 100644
--- a/dockerimg/pushdockerimg.go
+++ b/dockerimg/pushdockerimg.go
@@ -8,27 +8,49 @@
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 
 	"sketch.dev/dockerimg"
 )
 
 func main() {
+	if runtime.GOOS != "linux" || runtime.GOARCH != "amd64" {
+		fmt.Fprintf(os.Stderr, "pushdockerimg.go: requires ubuntu linux/amd64\n")
+		os.Exit(2)
+	}
+	// Display setup instructions for vanilla Ubuntu
+	fmt.Print(`Push a sketch docker image to the public GitHub container registry.
+
+	# One-off setup instructions:
+	sudo apt-get update
+	sudo apt-get install docker.io docker-buildx qemu-user-static
+	# Login to Docker with GitHub credentials
+	# You can get #GH_ACCESS_TOK from github.com or from 'gh auth token'.
+	# Make sure the token is configured to write containers for the boldsoftware org.
+	echo $GH_ACCESS_TOK | docker login ghcr.io -u $GH_USER --password-stdin
+
+This script will build and push multi-architecture Docker images to ghcr.io.
+Ensure you have followed the setup instructions above and are logged in to Docker and GitHub.
+
+Press Enter to continue or Ctrl+C to abort...`)
+	fmt.Scanln()
+
+	// Create a temporary directory for building
 	dir, err := os.MkdirTemp("", "sketch-pushdockerimg-*")
 	if err != nil {
 		panic(err)
 	}
 	defer os.RemoveAll(dir)
 
+	// Get default image information
 	name, dockerfile, tag := dockerimg.DefaultImage()
+
+	// Write the Dockerfile to the temporary directory
 	if err := os.WriteFile(filepath.Join(dir, "Dockerfile"), []byte(dockerfile), 0o666); err != nil {
 		panic(err)
 	}
 
-	fmt.Print(`NOTE: this requires:
-	brew install colima docker docker-buildx qemu
-	gh auth token | docker login ghcr.io -u $(gh api user --jq .login) --password-stdin
-`)
-
+	// Helper function to run commands
 	run := func(args ...string) {
 		cmd := exec.Command(args[0], args[1:]...)
 		cmd.Dir = dir
@@ -42,22 +64,25 @@
 
 	path := name + ":" + tag
 
-	run("colima", "start")
-	run("docker", "buildx", "create", "--name", "arm", "--use", "--driver", "docker-container", "--bootstrap")
-	run("docker", "buildx", "use", "arm")
-	run("docker", "buildx", "build", "--platform", "linux/arm64", "-t", path+"arm64", "--push", ".")
-	run("docker", "buildx", "rm", "arm")
-	run("colima", "start", "--profile=intel", "--arch=x86_64", "--vm-type=vz", "--vz-rosetta", "--memory=4", "--disk=15")
-	run("docker", "context", "use", "colima-intel")
-	run("docker", "buildx", "create", "--name", "intel", "--use", "--driver", "docker-container", "--bootstrap")
-	run("docker", "buildx", "use", "intel")
-	run("docker", "buildx", "build", "--platform", "linux/amd64", "-t", path+"amd64", "--push", ".")
-	run("docker", "buildx", "rm", "intel")
-	run("docker", "context", "use", "colima")
-	run("colima", "stop", "--profile=intel")
-	run(
-		"docker", "buildx", "imagetools", "create",
-		"-t", path, path+"arm64", path+"amd64",
+	// Set up BuildX for multi-arch builds
+	run("docker", "buildx", "create", "--name", "multiarch-builder", "--use")
+
+	// Make sure the builder is using the proper driver for multi-arch builds
+	run("docker", "buildx", "inspect", "--bootstrap")
+
+	// Build and push the multi-arch image in a single command
+	run("docker", "buildx", "build",
+		"--platform", "linux/amd64,linux/arm64",
+		"-t", path,
+		"--push",
+		".",
 	)
+
+	// Inspect the built image to verify it contains both architectures
 	run("docker", "buildx", "imagetools", "inspect", path)
+
+	// Clean up the builder
+	run("docker", "buildx", "rm", "multiarch-builder")
+
+	fmt.Printf("\n✅ Successfully built and pushed multi-arch image: %s\n", path)
 }