How many movies have Frederik de Groot and Martijn van Nellestijn collaborated on?

They have worked on 4 movies together! Their first movie together was Sinterklaas en het Uur van de Waarheid (2006) and was their highest rated movie together. They have not worked together since Sinterklaas en het raadsel van 5 december (2011). They are most known for their family films together.