uninitialized constant ActiveSupport::Notifications with 0.5.6 on rails 2.3.14

[jomz]

NameError (uninitialized constant ActiveSupport::Notifications):
  vendor/bundle/ruby/1.9.1/gems/activesupport-2.3.14/lib/active_support/dependencies.rb:469:in `load_missing_constant'
  vendor/bundle/ruby/1.9.1/gems/activesupport-2.3.14/lib/active_support/dependencies.rb:106:in `const_missing_with_dependencies
'  vendor/bundle/ruby/1.9.1/gems/lacquer-0.5.6/lib/lacquer/varnish.rb:17:in `block in purge'
  vendor/bundle/ruby/1.9.1/gems/lacquer-0.5.6/lib/lacquer/varnish.rb:16:in `each'
  vendor/bundle/ruby/1.9.1/gems/lacquer-0.5.6/lib/lacquer/varnish.rb:16:in `all?'
  vendor/bundle/ruby/1.9.1/gems/lacquer-0.5.6/lib/lacquer/varnish.rb:16:in `purge'
  vendor/bundle/ruby/1.9.1/gems/radiant-lacquer-extension-1.0.0/lib/lacquer/resource_controller_extension.rb:29:in `purge_all_p
ages'

Probably introduced by c447853