Samson Lee believes Wales' scrum problems that surfaced against World Cup rivals England two days ago are "100 per cent fixable".
Wales conceded four scrum penalties at Twickenham and came off second-best in that critical set-piece area for much of the contest.
But despite issues up-front, they finished comfortably the stronger team and claimed a dramatic 28-25 Pool A victory that kept them firmly on course for the quarter-finals.
"I t was a tough day at the office," said Scarlets tighthead prop Lee, who went on as a substitute early in the second period.
"We always knew they were going to be a difficult pack to go up against.
"We have to sort out whatever we need to get right and then take it into the Fiji match on Thursday. The problems are 100 per cent fixable.
"We lost most of the hits in the scrum and ended up soaking up the hits, so this week we have to get our speed right going into the scrum.
"No-one is going to be happy with Wales coming second in the set-piece. So we will get it right this week and get our speed back.
"We discussed it in the changing room after the game. I t was down to our mistakes. Our speed on the hit wasn't right."
Lee looks set to start against Fiji in Cardiff on Thursday following injury troubles that have stalled his progress this year.
A serious Achilles problem kept him out for six months, then he experienced a tight calf muscle during the 54-9 World Cup victory over Uruguay eight days ago.
" I feel much better going into this game," he added. "Every match I play, I will feel better in terms of my fitness. I feel pretty good in myself at the moment.
"The Fijian pack has improved over the years, so this game will be really tough.
" We need to have a better day at the office in the set-piece. If we get that right we are capable of taking anyone on."