Firefighters tackled a blaze at an industrial unit in Ilkeston overnight.
Crews were called to Bath Street just after 11.30pm on Friday.
They used water from two pumps to douse the fire in a small outbuilding on the derelict site.
It is understood that nobody was injured in the blaze but the extent of the damage is unknown.
Firefighters left the scene at about 2.40am.