Trouble with output name in MkvToolNix Merge (GUI)

When I use some french current letters (accents for ex.), the output name is wrong. Ex: I create a file named "Mon amie Adèle.mkv", the output file name is "Mon amie Adèle.mkv" every non-standard ASCII code (I mean out of A to Z) seems to have potentially an issue.

But, anyway, thanks for your great job !