diff --git a/cinny/lotus_deploy.sh b/cinny/lotus_deploy.sh
index 2eb0f73..f1e1ab1 100755
--- a/cinny/lotus_deploy.sh
+++ b/cinny/lotus_deploy.sh
@@ -160,7 +160,13 @@ echo "[$(date '+%Y-%m-%d %H:%M:%S')] Deploying to $WEBROOT..."
 # /var/www/html/config.json by lxc106-cinny.sh. The build ships a DEV default
 # (allowCustomHomeservers:true); rsyncing it would clobber the production config
 # on every deploy. Keep the app bundle and the runtime config separate.
-rsync -a --delete --exclude config.json dist/ "$WEBROOT/"
+# [matrix #23] Keep the previous builds' hashed assets for a while: a browser
+# still holding an older index.html (or service-worker precache) asks for its
+# assets/index-<old hash>.js, and deleting them on every deploy broke the app
+# for those users until their cached shell expired. Prune after 14 days.
+rsync -a --delete --exclude config.json --exclude assets/ dist/ "$WEBROOT/"
+rsync -a dist/assets/ "$WEBROOT/assets/"
+find "$WEBROOT/assets" -type f -mtime +14 -delete
 
 echo "[$(date '+%Y-%m-%d %H:%M:%S')] ===== Deploy complete ($VITE_APP_VERSION) ====="
 
diff --git a/cinny/nginx.conf b/cinny/nginx.conf
index 6e4a797..97dbd41 100644
--- a/cinny/nginx.conf
+++ b/cinny/nginx.conf
@@ -1,3 +1,12 @@
+# [matrix #23] SPA routes (/, /home/…, /login/…) are rewritten to /index.html
+# inside `location /`, where no cache headers were set: browsers then reused a
+# heuristically fresh shell after a deploy and requested deleted assets. Only
+# the rewritten shell gets no-cache; other files there keep their defaults.
+map $uri $lotus_shell_cache_control {
+    /index.html "no-cache, no-store, must-revalidate";
+    default     "";
+}
+
 server {
     listen 80;
     listen [::]:80;
@@ -99,6 +108,9 @@ server {
     }
 
     location / {
+        # add_header here drops the server-level headers, so include them again.
+        include snippets/cinny-security-headers.conf;
+        add_header Cache-Control $lotus_shell_cache_control always;
         rewrite ^/config\.json$          /config.json break;
         rewrite ^/manifest\.json$        /manifest.json break;
         rewrite ^/sw\.js$                /sw.js break;