Favicon showing on the right side of the tab

After upgrading to Firefox 53, both favicons and tab numbers are showing on the right side of the tab.

I have tried without a pentadactylrc as well, but it makes no difference.

:ver
Pentadactyl 7307 (created 2017/02/14 23:43:28) running on:
Mozilla/5.0 (X11; Linux x86_64; rv:53.0) Gecko/20100101 Firefox/53.0

[gpelouze]

I’m having this bug as well, with the same Firefox and Pentadactyl versions.