Backlight adjustment buttons on Thinpad T495 don't work

I don't see any events when I run xev and press either the brightness up or down keys. I have configured i3wm to handle the XF86MonBrightnessDown and XF86MonBrightnessUp, but they won't get triggered because they are never published. Using the brillo command to change the brightness from the command-line works great as a workaround, but it is really nice to be able to use the keys instead. I'm running Arch Linux with kernel version 5.14.12-arch1-1.