imagemagick mogrify not cropping pictures in place as expected

I would like to crop all the images in a directory in place. This works to create a cropped copy of a file:

magick slide.jpg -crop 1700x1100+0+550 slide-cropped.jpg

I thought I would be able to make the same change in place with this command:

magick mogrify slide.jpg -crop 1700x1100+0+550 

While this does modify the file slide.jpg (as shown by ls -l), it does not crop it.

Is there a way to get magick to crop files in place?

I’m using ImageMagick 7.1.1-43 Q16-HDRI x86_64 22550 on OS X Sequoia.