diokuz-yarn-nested-dedupe-b v2.0.0

Yarn does not dedupe nested dependencies

So, I have a repo with four dependencies:

diokuz-yarn-nested-dedupe-a
diokuz-yarn-nested-dedupe-b
diokuz-yarn-nested-dedupe-c
diokuz-yarn-nested-dedupe-d

a and b depends on diokuz-yarn-nested-dedupe-dep@1.0.0, but c and d depends on diokuz-yarn-nested-dedupe-dep@2.0.0

1.0.0 is deduped to root node_modules, but there are two absolutely equal versions of 2.0.0 version in diokuz-yarn-nested-dedupe-c/node_modules and in diokuz-yarn-nested-dedupe-d/node_modules.

WHY?