In 2013 Derus was finally able to compete in para athletics and was classified as a T47 sprinter. He entered his first major international competition that year, representing Poland at the 2013 IPC Athletics World Championships in Lyon. There he won a gold in the 100 metre sprint and a silver in the 200 metre. He followed this with double gold in both events at the 2014 IPC Athletics European Championships in Swansea. In 2015 he successfully defended his World 100 metre title in Doha, and again won silver in the 200 metres. The 2015 World Championships also saw Derus compete in the long jump, finishing ninth with a distance of 6.24m.