Code macro fails to escape properly in GWT editor

This only happens with the GWT editor, but whenever I enter a code macro containing XML comments, it fails to render it properly. The following snippet fails when edited in the GWT editor (works when edited in the Wiki editor):

<?xml version="1.0" encoding="UTF-8"?>
<!-- this is a test -->
<test>123</test>

This changes the text to:

<?xml version="1.0" encoding="UTF-8"?>
<!== this is a test 

Very minor, since it works in the Wiki editor, but good to have...