Git-flow release finished: brought to develop instead of master

Question

Here's what I've done:

(develop)$      ...
(develop)$      git flow release start v0.1
(release/v0.1)$ git flow release finish v0.1
(master)$       git checkout develop
(develop)$      ...

Why have I to run checkout develop ?
Git-flow should bring me back to develop branch instead of master.

If it can help to spot the problem, here is what happens after my git flow release finish v0.1:

Branches 'master' and 'origin/master' have diverged.
And local branch 'master' is ahead of 'origin/master'.
Switched to branch 'master'
Your branch is ahead of 'origin/master' by 1 commits.
Merge made by recursive.
helloworld.txt        |    1 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Deleted branch release/v0.1 (was 34bb27e).

Summary of actions:
- Latest objects have been fetched from 'origin'
- Release branch has been merged into 'master'
- The release was tagged 'v0.1'
- Release branch has been back-merged into 'develop'
- Release branch 'release/v0.1' has been deleted