...
# Everyone gets English language support added
my $lang = $r->header_in('Accept-Language');
$r->header_in('Accept-Language', $lang . ', en;q=0.20');
return OK;

##</code><code>##

...
# English language added as failsafe
my $lang = $r->header_in('Accept-Language');
if ($lang !~ /en/ || $lang !~ /de/) {
  $r->header_in('Accept-Language', $lang . ', en;q=0.20');
  return OK;
} else {
  return OK;
}