diff --git a/conf/nginx.conf b/conf/nginx.conf
index 5d7c08d..a5f3122 100644
--- a/conf/nginx.conf
+++ b/conf/nginx.conf
@@ -1,7 +1,7 @@
 #sub_path_only rewrite ^__PATH__$ __PATH__/ permanent;
 location __PATH__/ {
   proxy_pass http://localhost:__PORT__/;
-  add_header X-Frame-Options SAMEORIGIN;
+  more_set_headers "X-Frame-Options: SAMEORIGIN";
   proxy_set_header    Host $host;
   proxy_http_version 1.1;
   proxy_set_header Upgrade $http_upgrade;