Safari downloads images in jpg format

Just recently, when I right-click on an image in Safari and choose 'save image as', Safari has started forcing me to save it as a webarchive. Before this, it had always saved it in whatever format the image was in, eg jpg, png, gif, whatever.

I DO NOT want to save images as webarchives. How do I save images in their native format?

There are annoying work-arounds, eg if I first choose 'open image in a new tab', and then right-click on that and choose 'save image as', Safari does save the image in whatever format the image was in, eg jpg, png, gif. But that is supremely annoying -- the kind of kludge I expect to have to resort to with MS products, not Apple products.

Unless someone has a better solution (a preference somewhere that I haven't found, an extension), or until Apple restores the previous behavior, I have switched to Firefox as my principal browser.