method_missing: undefined method `increment_open_transactions` database_cleaner

When using database_cleaner (0.9.1) with rails (4.1.0) {my home path}/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/activerecord-4.1.0/lib/active_record/dynamic_matchers.rb:26:in `method_missing’: undefined method `increment_open_transactions’ for ActiveRecord::Base:Class (NoMethodError) from {my home path}/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/database_cleaner-0.9.1/lib/database_cleaner/active_record/transaction.rb:13:in `start’ from {my home path}/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/database_cleaner-0.9.1/lib/database_cleaner/base.rb:73:in `start’ from {my home path}/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/database_cleaner-0.9.1/lib/database_cleaner/configuration.rb:75:in `block in start’ from {my home path}/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/database_cleaner-0.9.1/lib/database_cleaner/configuration.rb:75:in `each’ from {my home path}/.rbenv/versions/2.1.1/lib/ruby/gems/2.1.0/gems/database_cleaner-0.9.1/lib/database_cleaner/configuration.rb:75:in `start’ Somehow we were using an old version of database_cleaner, gem “database_cleaner”, […]