diff --git a/docker/examples/arm64/docker-compose.yml b/docker/examples/arm64/docker-compose.yml
index 471fb402b..985bbbdec 100644
--- a/docker/examples/arm64/docker-compose.yml
+++ b/docker/examples/arm64/docker-compose.yml
@@ -2,6 +2,9 @@ version: '3.5'
 
 # Example Docker Compose config file for PhotoPrism (Raspberry Pi and other ARM-based devices)
 #
+# ATTENTION: You have to boot your Raspberry Pi 3 / 4 with the parameter "arm_64bit=1"
+#            in config.txt to use our ARM64 image.
+#
 # IMPORTANT: When installing PhotoPrism on a public server outside your home network, please
 #            always run it behind a secure HTTPS reverse proxy like Traefik, Caddy, or NGINX.
 #            Your files and passwords will be transmitted in clear text otherwise.