paper_trail: After installing paper_trail, get "irb: warn: can't alias context from irb_context." from rails console

I’ve tested this by running rails c both before and after git stash. On Rails 4.1 in Mavericks, after following the instructions to add the versions table and adding has_paper_trail to three models, whenever I run rails c I get

irb: warn: can't alias context from irb_context.

I’ve spent some time Googling without much luck, there’s old threads talking about rspec, but I don’t see how that’s relevant since I’m not using it. Any ideas why this is happening?