diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index f2557e32..6038b28c 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -1357,6 +1357,14 @@ my $update_vm_api  = sub {
 			if defined($conf->{pending}->{$opt});
 
 		    &$create_disks($rpcenv, $authuser, $conf->{pending}, $arch, $storecfg, $vmid, undef, {$opt => $param->{$opt}});
+
+		    # append new CD drives to bootorder to mark them bootable
+		    my $drive = PVE::QemuServer::parse_drive($opt, $param->{$opt});
+		    if (PVE::QemuServer::drive_is_cdrom($drive, 1)) {
+			push @bootorder, $opt;
+			$conf->{pending}->{boot} = PVE::QemuServer::print_bootorder(\@bootorder);
+			$modified->{boot} = 1;
+		    }
 		} elsif ($opt =~ m/^serial\d+/) {
 		    if ((!defined($conf->{$opt}) || $conf->{$opt} eq 'socket') && $param->{$opt} eq 'socket') {
 			$rpcenv->check_vm_perm($authuser, $vmid, undef, ['VM.Config.HWType']);