Millwall have signed Reading defender Jake Cooper on a three-year deal for an undisclosed fee.

Cooper, 22, spent the second half of last season on loan at the Lions.

He made 18 appearances for the club and helped Neil Harris’ side win promotion from League One.

Cooper told Millwall’s official website: “I'm really pleased to be back here and to have secured my long-term future.

“We've had to be patient to get the deal done and I'm relieved everything is now complete and I can focus on my football.

“It was an incredible experience to be a part of what we achieved at Wembley and I can't wait to get stuck in again with what is a great group of lads.

“Thankfully I've been training and playing in pre-season games since the start of the summer so I'm fit and raring to go.”

MORE: Millwall make move for Championship defender - report

Cooper was one of Harris’ top transfer targets this summer, and he is happy to have finally landed his man.

The Lions boss added: “I'm delighted that we have been able to bring Jake back to the club on a permanent basis.

“I've made no secret of my appreciation and respect for how he performed last season and how we've been so keen to sign him this summer.

“He has signed a long-term contract so he can realise his potential at Millwall. Jake has a strong personality and is a player who is capable of strong performances. I'm very confident that he can go on to become a top, top centre-half for this club.

“I'd once again like to thank the chairman and the rest of the board for their support in getting this deal over the line.”