Ikea Step Stool Stability feet

I adapted the Ikea Step Stool to a Montessori tower. This makes a kind of tower from the known Ikea Step Stool. That way your 2 year-old child can "stand" next to you in the kitchen en help you where needed :-). I found this Idea online.

The only negative thing about using this Ikea Step Stool as a base for the Montessori tower was stability. When my son gets to enthusiastic about making waffles with me, he starts moving in all directions (don't ask me why :-) ) and the tower sometimes gets