Subtitle language setting not working

Currently I use Subtitles to automatically download all the subtitles in English and Dutch. It names the subtitles like this:

TVShow.S01E01.mp4
TVShow.S01E01.en.srt
TVShow.S01E01.nl.srt

In Infuse I have set that the default subtitle language should be Dutch. But when I start a TV show it always uses the English subtitle file. Is there something wrong with how the srt files are named? Or should I change something else?