Maximum penalties in Wales for breaching lockdown will rise to £1,920, the Welsh Government has confirmed.
First Minister Mark Drakeford has faced calls to raise the penalties to deter breaches.
Initial fixed penalties will stay the same at £60, but will double for each time someone is caught.
But the police and crime commissioner (PCC) for Dyfed-Powys Police said the changes to penalties do not go far enough.
PCCs had been pushing for tougher penalties, amid claims Wales' tougher restrictions are more difficult to enforce when they were lower than in England.
They wanted Wales to adopt the same structure to England, where the first penalty recently increased to £100, doubling for each successive offence to a maximum of £3,200.
Dafydd Llywelyn, PCC for Dyfed-Powys, told BBC Radio Wales Breakfast: "Personally, I don't think it goes far enough if I'm honest.
"It's pleasing that Welsh Government have listened to policing in Wales, [but] I'm personally disappointed that the first fine hasn't been altered as a deterrent."
The 14-day discount remains in place for first offences. In Wales it means someone who quickly settles a fixed penalty notice pays £30.
The Welsh Government said the new structure, coming into force on Friday, was being introduced ahead of the bank holiday weekend.
The police will also still have the powers to charge a person with a criminal offence, which can incur a higher fine.
Mr Drakeford said: "The police have adopted a '4Es' approach to the regulations - they have engaged people, explained what they need to do and encouraged them to comply. But when people haven't responded, they have used their powers to enforce the regulations.
"Fines are a last resort in the enforcement of the regulations which keep us all safe.
"The evidence from the chief constables and police and crime commissioners shows we need a stronger fines structure to deter that small minority of people who persistently fail to keep to the rules."
But in an email to Wales' PCCs from a Welsh Government police liaison officer, seen by BBC Wales before the announcement, Mr Drakeford was said not to be "convinced that there is currently enough evidence available to him to increase the starting level for fines".
Evidence from the four police forces show a small minority breaking the regulations, "particularly by traveling to well-known beauty spots throughout Wales", the Welsh Government said.
A total of 1,300 fixed penalty notices have been issued since lockdown restrictions were introduced.
How will the new penalties work in Wales?
Up until now, fines have been pegged at £60 for a first offence and £120 for subsequent offences.
But England has used a multiplier, where each subsequent offence doubles the amount.
The change will mean that a multiplier will also apply in Wales. The second offence will be £120, and from then it doubles, maxing out at the sixth offence when a £1,920 charge will apply.
Earlier in May the UK government loosened restrictions around exercise, allowing people to drive, but increased penalties.
Stay at home restrictions remained in place in Wales but the penalties did not increase.
Last weekend there were reports of visitors breaking restrictions in Welsh beauty spots, including some from Manchester, Norwich and London.
The announcement of the increase to penalties by the Welsh Government followed a vote in a virtual Senedd meeting, where ministers supported a Plaid Cymru amendment calling for an increase to maximum fines.
After they saw the email from the police liaison, Plaid Cymru Dyfed Powys PCC Dafydd Llywelyn and Arfon Jones, commissioner for the North Wales force, said in a statement "Wales' police chiefs have been ignored" because Wales was not bringing the penalties "in parity with those handed out in England".
'Finally seen sense'
Later, Plaid Cymru Leader Adam Price said: "The Labour Welsh Government have finally seen sense and raised the maximum fines for those breaking lockdown rules in Wales from £120 to £1,920.
"This latest U-turn from the government is a victory for common sense and to the perseverance of our police forces who are doing heroic work in protecting our communities during this crisis.
"However, the decision not to raise the minimum fines in parity with England as requested by the All Wales Policing Group remains bitterly regrettable."