TTT server changing map when I don't want it to

I just want it to stay on one map until I manually change it with a console command. I already have ttt_round_limit and ttt_time_limit_minutes set to 0, but it keeps changing maps. Am I missing something?

Edit: My server even says “The map will change in 0 rounds or 00:00:00”. WTF?

Edit 2: Ok, it seems that “0” isn’t an acceptable value. I changed the round limit to 999 and the time limit to 300 (5 hours), and the map hasn’t changed yet. I’ll post again if it does.