diff --git a/redmine.subdomain.conf.sample b/redmine.subdomain.conf.sample
new file mode 100644
index 00000000..8918a41d
--- /dev/null
+++ b/redmine.subdomain.conf.sample
@@ -0,0 +1,28 @@
+## Version 2025/05/04
+
+server {
+    listen 443 ssl;
+    listen [::]:443 ssl;
+
+    server_name redmine.*;
+
+    include /config/nginx/ssl.conf;
+
+    client_max_body_size 0;
+
+    access_log /var/log/nginx/redmine-access.log;
+    error_log /var/log/nginx/redmine-error.log;
+
+    location / {
+        include /config/nginx/proxy.conf;
+        include /config/nginx/resolver.conf;
+
+        set $upstream_app redmine;
+        set $upstream_port 3000;
+        set $upstream_proto http;
+        proxy_pass $upstream_proto://$upstream_app:$upstream_port;
+
+        proxy_set_header Host $http_host;
+        client_max_body_size 10m;
+    }
+}