Delayed_job: undefined method `handle_asynchronously' for #<Class:0x4601b08>

After deploying DelayedJob as a gem, I got the following error:

undefined method `handle_asynchronously' for #<Class:0x4601b08>

Same code works when I deploy DelayedJob as a plugin.

I have tried the solution suggested by this SO question and I sti开发者_如何学JAVAll get the same error.

I am using DelayedJob 1.8.4, Windows XP, Rails 2.3.5.

I had a model called DelayedJob in my models directory. I added this model to query the job queue. This conflicted with the delayed_job.rb file. I renamed the file and the problem went away.