Steps to reproduce, create a file with a namespace, class and method:

namespace Foo;

class Bar
{
    function biteMe(callable $where)
    {
       //...
    }
}

Now begin adding a DocBlock comment to the method. After the usual "/**" <ENTER> shortcut, the auto generated @param/@return will prefix the 'callable' type with the current namespace:

/**
 *
 * @param Foo\callable $where
 */
function biteMe(callable $where)


As an aside, I find this strange since 'bool', 'int', 'float' and 'string'; introduced with PHP 7, work, but 'callable' introduced with PHP 5.4, doesn't.