RKC Waalwijk right-back Jordi Altena will join Scottish Premiership leaders Heart of Midlothian on 1 January for an undisclosed fee.
The 22-year-old former Vitesse Arnhem player, who has made more than 50 senior appearances, has agreed a deal until the end of the 2028-29 season.
The transfer is subject to Scottish FA approval and international clearance but he could feature in Hearts' next game at home to Livingston on Saturday.
Derek McInnes' side lead the top flight by three points but second-placed Celtic play their game in hand away to Motherwell on Tuesday evening.
"It's good that we're able to get our business started so early," McInnes told the club's website.
"We've got a strong squad here, with options all over the park, but I have spoken before about strengthening in some areas, and I feel that's what we've done by bringing Jordi in.
"He's got the attributes that we feel can make him a success here at Hearts and hopefully the way he plays will excite the fans."