after upgrading RSpec to version 3 I can't run single spec file anymore

We are in the process of upgrading rails from 3.4 to 4.2. When we upgraded the rspec to the latest version, even after forcing the rspec to run only one spec it runs around 900 tests but my file only hast two contexts. I use something similar to this command :

rspec spec/myfile_spec.rb

What can be wrong? Is it something that I can fix in spec_helper? I d