How do I stop "DEFAULT.esp" from appearing?

[Omny]

I'm working on a mod in GECK but lately this esp called "DEFAULT.esp" keeps appearing in my mod list as a master for my mod. Whenever I try to delete it and get rid of my mod's reliance on it as a master, it just reappears if I open the GECK and save my mod again. How do I stop this from happening?

[madmongo]

Did you somehow create a mod that doesn't have FalloutNV.esm as a master?