Major work has begun to replace two of Heage Windmill's six sails.
Many residents have noticed that only four sails are currently visible and Heage Windmill Society trustees say work is progressing well.
Founder trustee Alan Gifford said: "We have purchased a set of purpose made timbers required and the sails are being assembled at the mill by our volunteers.
"We have been preparing for assembly the timber for the replacement pair of sails.
"There are we find some 84 separate pieces of wood involved in the construction of these new sails and each piece had first had any knots treated, then been coated with sealer and we are now in the process of undercoating and glossing.
"The surface areas to be thus treated are in fact quite large."
The £20,000 cost of the work is being covered by money taken from the mill maintenance fund of Heage Windmill Society - but donations are welcome.
Volunteers are continuing to mill flour with four sails and the normal range flour is still on sale.
The windmill will be open every weekend until the end of October.