PHP encoded with Zend Guard and composer

Question

My composer.json file contains

{
...
"autoload":{
"classmap":["src/"]
}
...
}

src/ contains encoded PHP files.

But when I try to run php composer.phar update --no-dev it generates the vendor/composer/autoload_classmap.php file without any mapping.

There are solution actually - to make update vendors with Composer before encode them, but this is has no-sense and every time when somebody updates Composer autoloader, I need to encode all project again.