Cucumber, Capybara validating HTML and testing JavaScript together fails

I've recently added html validation to my cucumber features. I'm using the gem be_valid_asset which works really well until Cucumber hits a @javascript flagged feature. T开发者_JAVA技巧his kicks in culerity (I've tried selenium for this as well) and then the html validation fails.

The reason the validation fails is that both culerity and selenium appear to remove the doctype from the page.

Has anyone else had this?

Change in strategy mentioned above is working a treat