The last modifications to the castle were the work of Organisation Todt workers in 1942–4 on behalf of the German occupiers. They demolished the barracks and built four concrete machine-gun positions, three 5 cm mortar positions, trenches, four tobruk pits, and personnel shelters. The defences in "Stützpunktgruppe Talfeste" also featured flame throwers, two 60 cm searchlight positions, and two 10.5cm K331(f) field guns.