perl6 module use problem

#### FILE: lib/A/B.pm6

our class A::B is export;
method a { say "A::B.a"; }

#### FILE: lib/A.pm6

module A;
use A::B;
our constant B = A::B;
our sub v is export { say "A::v"; }

#### Invoke with perl6 -I lib/ -e 'use A; my $b = B.new;'

#### I get:
===SORRY!=== Error while compiling -e
Undeclared name:
    B used at line 1