How to use Rewrite and ProxyPass without affecting the Cookies

We are using proxypass with a rewrite rule that modifies the value of the location in the header.

if { [HTTP::is_redirect] } {

     HTTP::header replace Location [string map {inside.domain.com outside.domain.com} [HTTP::header Location]]

 }

Unfortunately, this is causing responses with multiple Set-cookie headers to lose all but the 1 of them.

Is there a way to modify the location header without truncating the multiple headers with the same name?