As per the api docs:
If you wish to disable this emulation (which was the default behavior in versions 0.13.1 and earlier) you can add the following line to your application.rb file:
ActiveRecord::ConnectionAdapters::Mysql[2]Adapter.emulate_booleans = false
But when I do so, I get:
uninitialized constant ActiveRecord::ConnectionAdapters::Mysql2Adapter
The docs don’t ask you to require activerecord in application.rb. Requiring it solved the problem.