diff --git a/pgadmin.subdomain.conf.sample b/pgadmin.subdomain.conf.sample
index 8f45fc7..66c9840 100644
--- a/pgadmin.subdomain.conf.sample
+++ b/pgadmin.subdomain.conf.sample
@@ -42,6 +42,9 @@ server {
         set $upstream_proto http;
         proxy_pass $upstream_proto://$upstream_app:$upstream_port;
 
+        # Hide proxy port to prevent CSRF errors
+        proxy_hide_header X-Forwarded-Port;
+
         # Uncomment to allow loading in an iframe (i.e. Organizr)
         #proxy_hide_header X-Frame-Options;
     }