Ceramic tile over OSB "flake board"?

Hello, My wife and I are putting ceramic tile in our bathroom. The subfloor is pine plank with a 1/2" OSB (Flake/Chip board) on top with self stick vinyl. Do I need to put cement board in? or can I remove the vinyl and put the tile on the OSB?
Thanks :)

I would remove the OSB, and go with cement board over the wood planking.