Apache 2.2 Reverse Proxy fails to load the images

I am trying to setup a reverse proxy to my firewall through my internal webserver.

WAN -开发者_如何转开发> port 80 (rewrite to port 443) -> Internal Webserver -> Virtualhost -> Reverse proxy -> Firewall

This is my config:

ProxyRequest Off
ProxyPreserveHost Off

ProxyPass /firewall/ http://192.168.1.1/

<Location /firewall/>
ProxyPassReverse /
ProxyHTMLURLMap / /firewall/
</Location>

When I visit the site I still have images which are like this:

/themes/image.png

Which then points to https://subdomain.bla.com/themes/image.png

What I need is them to be:

/firewall/themes/image.png 

Which then points to: https://subdomain.bla.com/firewall/themes/image.png

Try adding the following:

 ProxyHTMLURLMap http://192.168.1.1  /firewall

below the ProxyPass directive.