DD-WRT Mac address clone resets itself upon startup

1) Go to Web interface > Administration> Commands
2) Paste this:

nvram set wan_hwaddr=“12:40:CC:11:00:00″

nvram commit

stopservice wan
startservice wan

Not that:
„12:40:CC:11:00:00“ is my MAc address and you need to type your own there!

3) Click Save Startup