[users@httpd] Is there a way to return non-200 status when HHVM backend is down?

[linux.il]

Hi,
I'm running Apache 2.4 with HHVM backend (.php processing is going to HHVM
on :9000 with
ProxyPassMatch directive).
>From time to time HHVM  service is freezing, so PHP stuff return 503, but
static pages work as usual. I'd like Apache to return 503 or any non-200
status for static pages  in this situation. How this can be done?

TIA,
Vitaly