Out-of-contract Stockport defender Johnny Mullins has joined Rotherham on a two-year contract.
After returning to the club for pre-season training whilst out of contract, Mullins has now taken up a new deal with the Millers.
Mullins made 69 league appearances for Stockport after joining the club from Mansfield in 2008.
A club statement on Stockport's official website read: "Everybody at Stockport County wishes Johnny the very best of luck in the future."
Mullins told Rotherham's official website: "I am over the moon with the deal.
"The club didn't have to be sold to me. I knew a lot about Rotherham, the manager wanted me and I wanted to sign so that made the deal very easy.
"The first impressions of the club are very good, I have played against Ronnie Moore's teams before and I have always liked the way his full-backs play."