Nginx Proxy_Hide_Header and Variable

I need to hide some headers for a specific path. I have the following nginx config:

server {
  listen 80;

  location / {
    set $x_hide_header "X-Foo-Bar";

    if ($uri ~ "some-path$") {
      set $x_hide_header "Header-I-Need-To-Hide";
    }

    proxy_hide_header $x_hide_header;
    proxy_pass 
  }
}

But the header still exists. If I add proxy_hide_header "Header-I-Need-To-Hide" it disappears, but I need to hide it only for a specific path, as was said above. Looks like nginx interprets the variable in proxy_hide_header as string literal. Is there any workaround?

I can do this by defining another location and copying all from the current one + proxy_hide_header, but I won't do this. Maybe there is another solution?