Actually, this was found by @gergely-ujvari, here: https://github.com/hypothesis/h/commit/c2286994a215283addd86170851e4cabf3e97ca9

I just copied this change (and few related others) to my branch in https://github.com/hypothesis/h/commit/2bd722459bd9f53f9f56782ead42d737a141152c .