Cannot add a user/group with UID/GID 999 using ipa user-add or group-add

Issue

• When I use ipa user-add to create a user with UID 999 (and/or GID 999), Red Hat Identity Management ignores the --uid or --gid options and assigns a random UID or GID.

# ipa user-add someuser --uid=999 --first=Some --last=User

Actual results:
Command output is:

(..)
UID: 1453600009
(..)

Expected results:
Command output is:

(..)
UID: 999
(..)