How to turn off MySQL strict mode in Rails

Upgrading to Rails 4, it seems MySQL strict mode is now on by default for Rails connections. I say this because my Rails app is getting “Mysql2::Error: Data too long for column” when saving a string value longer than 255 characters. Yet, I paste the same query into MySQL console (where global strict mode is reported to be off) and it works fine, just with truncation warnings. As further evidence, it says here “Rails 4 both use strict mode by default”.