helm: Alias in `requirements.yaml` not working

As the docs stating it should be possible to deploy the very same dependency of a chart more than once. The alias mechanism - AFAIK - is the vehicle for achieving this. But it seems to be broken some how.

$ helm version
Client: &version.Version{SemVer:"v2.4.2", GitCommit:"82d8e9498d96535cc6787a6a9194a76161d29b4c", GitTreeState:"clean"}
Server: &version.Version{SemVer:"v2.4.2", GitCommit:"82d8e9498d96535cc6787a6a9194a76161d29b4c", GitTreeState:"clean"}

$ helm create test
Creating test

$ cat -<<EOF >> test/requirements.yaml
dependencies:
  - name: redis
    version: 0.7.0
    repository: https://kubernetes-charts.storage.googleapis.com/
    alias: redis-one
  - name: redis
    version: 0.7.0
    repository: https://kubernetes-charts.storage.googleapis.com/
    alias: redis-two
EOF

$ helm dep update ./test
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "stable" chart repository
Update Complete. ⎈Happy Helming!⎈
Saving 2 charts
Downloading redis from repo https://kubernetes-charts.storage.googleapis.com/
Downloading redis from repo https://kubernetes-charts.storage.googleapis.com/

$ find test/charts
test/charts
test/charts/redis-0.7.0.tgz

I would have expected to see 2 charts as subcharts after dependency resolution. Do I have some misunderstanding here or this actually an issue?