diff --git a/Dockerfile b/Dockerfile
index f853e65..6066fa7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,7 +1,7 @@
 # Lightweight, non-root nginx serving the static site.
 # Runs as user "nginx" and listens on 8080, ready to sit behind an
 # external reverse proxy that terminates TLS and forwards requests.
-FROM nginxinc/nginx-unprivileged:1.31-alpine-slim@sha256:762e8e4e5e103817c4158400fc3753c8e713ff8153b8c3afbb458ae4572bc9a3
+FROM nginxinc/nginx-unprivileged:1.31-alpine-slim@sha256:22f839c5fb4007dc24d203a170a9e03fc185d660bfefc34ac6823a7aef085cbc
 
 COPY default.conf /etc/nginx/conf.d/default.conf
 COPY --chown=nginx:nginx index.html styles.css script.js messages.js /usr/share/nginx/html/