League One side Sheffield United have signed on-loan Burnley left-back Daniel Lafferty for an undisclosed fee, on a deal until June 2019.
Northern Ireland international Lafferty, 27, made 45 appearances for the Clarets after signing from Derry City in January 2012.
He has featured in 22 games for the Blades since joining on loan in August.
Lafferty is United's second signing of the transfer window, following the arrival of midfielder Samir Carruthers.
Meanwhile, midfielder James Wallace, 25, has had his contract terminated by the club.
Find all the latest football transfers on our dedicated page.