diff --git a/conf/nginx-primaryonly.conf b/conf/nginx-primaryonly.conf
index 2fb9972e..9f040c0d 100644
--- a/conf/nginx-primaryonly.conf
+++ b/conf/nginx-primaryonly.conf
@@ -6,6 +6,7 @@
 	location /admin/ {
 		proxy_pass http://127.0.0.1:10222/;
 		proxy_set_header X-Forwarded-For $remote_addr;
+		add_header X-Frame-Options "SAMEORIGIN";
 	}
 
 	# ownCloud configuration.