diff --git a/web/nginx.conf b/web/nginx.conf
index a66ccfd7..88170bb6 100644
--- a/web/nginx.conf
+++ b/web/nginx.conf
@@ -4,6 +4,12 @@ server {
   root /usr/share/nginx/html;
   index index.html index.htm;
 
+  # Caddy terminates TLS and proxies here over plain HTTP, so nginx must not
+  # guess scheme/port for its own directory-redirect (e.g. /blog -> /blog/):
+  # absolute_redirect would otherwise leak this container's internal
+  # http://host:3000 into the Location header sent to real visitors.
+  absolute_redirect off;
+
   location / {
     try_files $uri $uri/ /index.html;
   }