diff --git a/Dockerfile b/Dockerfile
index 0748446..ed2d94a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1
 
-FROM alpine:3.19 as rootfs-stage
+FROM alpine:3.19 AS rootfs-stage
 
 # environment
 ENV ROOTFS=/root-out
diff --git a/Dockerfile.aarch64 b/Dockerfile.aarch64
index c4468cb..825ae9e 100644
--- a/Dockerfile.aarch64
+++ b/Dockerfile.aarch64
@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1
 
-FROM alpine:3.19 as rootfs-stage
+FROM alpine:3.19 AS rootfs-stage
 
 # environment
 ENV ROOTFS=/root-out