Using xfwd option with http-proxy doesn't remove x-forwarded-* headers

I am making a reverse proxy with node-http-proxy. I have set the xfwd option in the options of createProxyServer, but it doesn't seem to affect the headers.

Here is a snippet of my code:

const proxy = httpProxy.createProxyServer({ 
    agent: httpsAgent,
    secure: true,
    ssl: options,          
    changeOrigin: true,
    xfwd: false // <--- doesnt delete X-Forwarded* headers
});

Can anyone reproduce this? Thanks.