diff --git a/docker/common/nginx/nginx.conf b/docker/common/nginx/nginx.conf
index 178d9e7f0..cacf5e0c3 100644
--- a/docker/common/nginx/nginx.conf
+++ b/docker/common/nginx/nginx.conf
@@ -7,6 +7,8 @@ server {
   root /usr/share/nginx/html;
   # SSL stuff for cloudflare proxy-ing - ignores SSL certificate and uses SNI
 
+  add_header Content-Security-Policy "default-src 'self';";
+
   proxy_ssl_verify off;
   proxy_read_timeout 1m;
   proxy_ssl_server_name on;