Why Paperclip makes a request when asked for url?

sc.image.url(:thumb)

What I see then in the logs:

[AWS S3 200 0.601484 0 retries] head_object(:bucket_name=>"****",:key=>"sc/images/000/000/526/original/file.jpg")

Why Paperclip does this request? It seems that it checks if the file still exists on the sever before giving the url, to avoid giving the broken ones.

Is there a way to stop it from doing the check so it simply returns the url without doing additional requests?