diff --git a/packages/create-app/templates/default-app/packages/backend/Dockerfile b/packages/create-app/templates/default-app/packages/backend/Dockerfile
index 682798b826..9a9f54e610 100644
--- a/packages/create-app/templates/default-app/packages/backend/Dockerfile
+++ b/packages/create-app/templates/default-app/packages/backend/Dockerfile
@@ -20,6 +20,10 @@ RUN apt-get update && \
 
 # From here on we use the least-privileged `node` user to run the backend.
 USER node
+
+# This should create the app dir as `node`.
+# If it is instead created as `root` then the `tar` command below will fail: `can't create directory 'packages/': Permission denied`.
+# If this occurs, then ensure BuildKit is enabled (`DOCKER_BUILDKIT=1`) so the app dir is correctly created as `node`.
 WORKDIR /app
 
 # This switches many Node.js dependencies to production mode.