http -> https redirect port not respecting offset

I'm using JBoss AS 8 with new undertow integration:
<subsystem xmlns="urn:jboss:domain:undertow:1.0">
<worker name="default" task-core-threads="12" io-threads="3"/>
<buffer-pool name="default" buffer-size="2048" buffers-per-slice="512"/>
<server name="default-server">
<http-listener name="http" socket-binding="http"/>
<https-listener name="https" socket-binding="https" security-realm="UndertowRealm" />
<ajp-listener name="ajp" socket-binding="ajp"/>
<host name="default-host" alias="localhost">
<location name="/">
<file path="${jboss.home.dir}/welcome-content" cache-buffer-size="1024" cache-buffers="1024"/>
</location>
</host>
</server>
<servlet-container name="default">
<jsp-config/>
</servlet-container>
</subsystem>
Socket-binding is
<socket-binding name="ajp" port="8009"/>
<socket-binding name="http" port="8080"/>
<socket-binding name="https" port="8443"/>
and port-offset is 700.
So listeners are created on 8709, 8780 and 9143.

But when accessing a secured page, I get redirected from http:8780 to https:8443 instead of https:9143.