Variable existence in extended layout depends on block usage

[janedbal]

Following example raises notice about undefined variable $var:

// view.latte
{extends './layout.latte'}
{var $var = 'ok'}


// layout.latte
{$var} // undefined variable

but this works:

// view.latte
{extends './layout.latte'}
{var $var = 'ok'}
{block #test}


// layout.latte
{$var}
{include #test}

This is very confusing behaviour. Is it possible to fix it?