zpool_usage negative

I have two pools, and one is returning a negative value:

OK - deadpool: usage 81.88% | deadpool=81.88%;85;90
OK - smolpool: usage -202.3% | smolpool=-202.3%;85;90

root@tofu[~]# zpool list
NAME           SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
deadpool      4.53T  3.14T  1.39T        -         -    17%    69%  1.00x    ONLINE  /mnt
freenas-boot   282G  5.28G   277G        -         -     0%     1%  1.00x    ONLINE  -
smolpool      1.62T   401G  1.23T        -         -     6%    24%  1.00x  DEGRADED  /mnt

I am using master right now.