Export from album not in correct order

Until a month ago I have used Aperture to manage my photos. I migrated the library to Photos.

My usual way of work when I have a new collection of photos from an event is importing the photos in an album (used Projects in Aperture, but an album in Photos will do), then select the best photos and arrange them in a new album (e.g. top 100 photos of the event). Then I export the photos in this album for sharing (e.g. share via iTunes with an iPad or share on dropbox).

Now this is not working anymore in Photos. The reason is that Photos exports the photos in more or less random order. When you then synchronize the folder to iPad via iTunes, or browse the photos in dropbox, they appear in the random order that export had chosen. This is definitely not desired, I want them displayed exactly in the order they appeared in the album (which is chronological order for many events).