EDIT: updated 2018.06.01 to be done properly Upon switching over to the excellent Telephone Line modeline theme from my previous Smart Mode Line, I was generally pleased by the exceptional look and feel of it. That is, until I fired up a PDF a while later and found I’d lost my page-numbers that had always been there. Eventually I was able to solve this problem by adding two items to my use-package statements, one for pdf-tools and a subsequent one for telephone-line.