Does rack-mini-profiler work with Rails 4?

I installed mini-profiler gem with Rails 4 rc1 (with postgres for db). It’s not providing any stats. My understanding is that I’m just supposed to include the gem, run bundle and then start the application and a window will appear in the browser showing load time. However, I’m getting nothing.

It works fine here these days. Must have been an old, now resolved issue.