diff --git a/iso/docker/Dockerfile.arm64 b/iso/docker/Dockerfile.arm64
index ce1fb5c..d56d7bf 100644
--- a/iso/docker/Dockerfile.arm64
+++ b/iso/docker/Dockerfile.arm64
@@ -4,13 +4,14 @@
 # Build:  ./build-iso-arm64.sh   (wrapper handles docker buildx)
 # Output: dist/orionos-arm64-<date>.iso
 
-FROM menci/archlinuxarm:aarch64
+FROM lopsided/archlinux:latest
 
 # disable pacman seccomp sandbox (breaks under QEMU / nested containers)
 RUN echo "DisableSandbox" >> /etc/pacman.conf
 
 # initialize pacman keys for ALARM
-RUN pacman-key --init && pacman-key --populate archlinuxarm
+RUN pacman-key --init && pacman-key --populate archlinuxarm 2>/dev/null || \
+    pacman-key --populate archlinux
 
 # install build tools
 RUN pacman -Syu --noconfirm && \