You shouldn't change it.
Since 1999 that the Network Working Group(NWG) wrote a memorandum listing the safe Top Level Domains(TLDs) for development.
Choose one of that list to have a future-proof solution.
Because some developers depend on some tools with this poor approach - I was one of them - you can use a hack to solve this: write badidea when the HSTS warning pops up.
Use this only as a temporary solution and dedicate your time upgrading, or helping upgrade, your tools.
EDIT: Other solutions here.
