diff --git a/Dockerfile b/Dockerfile
index 62c0cea..250d082 100755
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,9 @@
-FROM ghcr.io/hugomods/hugo:0.157.0 AS build
+# syntax=docker/dockerfile:1
+# Pin the build stage to the native build platform so Hugo runs once (never
+# under QEMU emulation). Hugo output is static HTML — identical across arches —
+# so there's no reason to run it per target arch. The runtime stage below stays
+# on TARGETPLATFORM, so multi-arch (amd64 + arm64) runtime images are preserved.
+FROM --platform=$BUILDPLATFORM ghcr.io/hugomods/hugo:0.157.0 AS build
 WORKDIR /tmp/hugo
 COPY . .
 RUN hugo --gc --minify