The problem you're dealing with here is that `journalized` is a polymorphic association. You can read up on them here: http://guides.rubyonrails.org/association_basics.html#polymorphic-associations In short, what you'll want here is something like this:

```ruby
issue = Issue.create!(...issue params...)
journal.journalized = issue
journal.update_issue_timestamp
issue.reload.updated_at.should == time
```