diff --git a/conf/nginx/webvirtcloud.conf b/conf/nginx/webvirtcloud.conf
index bbe22fbd..6ea2f575 100644
--- a/conf/nginx/webvirtcloud.conf
+++ b/conf/nginx/webvirtcloud.conf
@@ -29,7 +29,10 @@ server {
         proxy_connect_timeout 1800;
         proxy_read_timeout 1800;
         proxy_send_timeout 1800;
-        client_max_body_size 1024M;
+        # an ISO upload sends 32 MiB chunks; nothing else is large. nginx
+        # buffers a body to disk before the panel sees it: a bigger limit
+        # lets anyone fill that disk with unfinished requests
+        client_max_body_size 64M;
     }
 
     location /novncd/ {