diff --git a/templates/outline/docker-compose.yml b/templates/outline/docker-compose.yml
index 95072c8..2231a51 100644
--- a/templates/outline/docker-compose.yml
+++ b/templates/outline/docker-compose.yml
@@ -51,6 +51,10 @@ services:
     labels:
       - "traefik.enable=true"
       - "traefik.http.routers.outline.rule=Host(`${SUBDOMAIN}.${DOMAIN}`)"
+      # R-753: this app reads the LEFTMOST X-Forwarded-For entry, which a stranger writes once traefik keeps the
+      # tunnel's chain — so its chain is removed here (it then reads traefik's X-Real-Ip or peer; never forgeable).
+      - "traefik.http.middlewares.outline-xff.headers.customrequestheaders.X-Forwarded-For="
+      - "traefik.http.routers.outline.middlewares=outline-xff"
       - "traefik.http.routers.outline.entrypoints=websecure"
       - "traefik.http.routers.outline.tls=true"
       - "traefik.http.routers.outline.tls.certresolver=letsencrypt"