As Swindon gradually improved in Division Two, Calderwood led the defence, missing only thirteen league games over the next three years. At the end of this period, he led the Town to their first promotion to the top flight, after beating Sunderland in the playoff final at Wembley in 1990. Shortly afterwards, Swindon were demoted to the Third Division due to an irregular payments scandal. The club were reinstated to the Second Division after an appeal. Calderwood was arrested and questioned by the police with regard to the scandal, though was not ultimately charged with anything.