diff --git a/.gitea/workflows/build.yaml b/.gitea/workflows/build.yaml
index 2e9a99e..6542cea 100644
--- a/.gitea/workflows/build.yaml
+++ b/.gitea/workflows/build.yaml
@@ -15,7 +15,7 @@ on:
 
 jobs:
   build:
-    runs-on: linux/amd64
+    runs-on: ubuntu-latest
     container:
       image: gitea.tourolle.paris/dtourolle/jellylms-builder:latest
 
diff --git a/.gitea/workflows/release.yaml b/.gitea/workflows/release.yaml
index 46b63f8..0b5c345 100644
--- a/.gitea/workflows/release.yaml
+++ b/.gitea/workflows/release.yaml
@@ -13,7 +13,7 @@ on:
 
 jobs:
   build-and-release:
-    runs-on: linux/amd64
+    runs-on: ubuntu-latest
     container:
       image: gitea.tourolle.paris/dtourolle/jellylms-builder:latest
 
diff --git a/Dockerfile.builder b/Dockerfile.builder
index d17ed0f..35fb239 100644
--- a/Dockerfile.builder
+++ b/Dockerfile.builder
@@ -1,7 +1,10 @@
 # JellyLMS Builder Image
 # Pre-built image with .NET SDK and JPRM for building Jellyfin plugins
-# Build: docker build -f Dockerfile.builder -t gitea.tourolle.paris/dtourolle/jellylms-builder:latest .
-# Push:  docker push gitea.tourolle.paris/dtourolle/jellylms-builder:latest
+# Multi-arch (amd64 + arm64): CI runs on ubuntu-latest, which both the amd64 and the
+# ARM runners carry, so the image must exist for both.
+# Build + push (needs a docker-container buildx builder and arm64 binfmt/QEMU):
+#   docker buildx build -f Dockerfile.builder --platform linux/amd64,linux/arm64 \
+#       -t gitea.tourolle.paris/dtourolle/jellylms-builder:latest --push .
 
 FROM mcr.microsoft.com/dotnet/sdk:10.0