Approvals does not change state of dependent ticket

I have created a lifecycle with these defaults:

active => [qw(open approved stalled)],

/defaults => {//
// on_create => ‘new’,//
// approved => ‘approved’,//
// denied => ‘rejected’,/

if i understand the manual correctly, this should change the depending
tickets status to ‘approved’:

// When an approval is accepted, the status of depending tickets will
be changed to this value./

but that doesn’t happen. Have I done something wrong, or do I understand
this feature wrong? The lifecycle is applied to the queue, where the
original ticket is.
I know it is in use, because I can set the status “approved” to the
ticket manually. The default lifecycle doesn’t have this status.