Any Non-EU citizens working with Canterbury in Madrid?

Hi,. I have applyed for TEFL course in Madrid ( still waiting for a reply) that guarantees a job with them for the rest of the school year. I am from Croatia and I dont need a visa to stay for up to 90 days but since im supposed to continue working for the school they must arrange some kind of work permit for their non-eu applicants? I guess the school will clarify this for me if I get accepted but I would love to hear from someone who had the same experience.