The Welsh Rugby Union and Scottish Rugby say they will "donate directly" to Doddie Weir's motor neurone disease charity after next Saturday's autumn Test series opener between Wales and Scotland.
Both organisations have committed to donating a joint six-figure sum from proceeds of the Principality Stadium encounter to the My Name'5 Doddie Foundation, the WRU and Scottish Rugby said in a joint statement.
The WRU decide distribution of gate receipts from the game - estimates put that at around £3million - while it is understood that the SRU will receive a seven-figure sum for Scotland taking part.
Both Unions were criticised on social media and by former players over the weekend for not contributing to the foundation directly from those pots.
Former Wales fly-half Jonathan Davies was among those to voice concern, calling on the WRU to donate a percentage of ticket money to the charity.
The game launches this season's autumn Test series for both countries, with the Doddie Weir Cup at stake.
It will be attended by former Scotland and British and Irish Lions lock Weir, who announced last year that he is suffering from MND.
In addition, Scotland head coach Gregor Townsend and Wales assistant coach Shaun Edwards will be among guests at a fund-raising dinner later this week, while a match-day bucket collection is also planned in Cardiff.
"The Welsh Rugby Union and Scottish Rugby today confirmed they will donate directly to the My Name'5 Doddie Foundation after this weekend's match between the two nations," the statement read.
"The Unions together have committed to donating a joint six-figure sum from the proceeds of the game, with the associated visibility for the fight against motor neurone disease also providing an invaluable contribution."
A WRU spokesperson added: "We have listened to supporters and, while our initial motivation in supporting the My Name'5 Doddie Foundation was to help raise awareness for the fight against MND and the foundations' fundraising campaign, we have decided to make a direct donation."
The news was welcomed by My Name'5 Doddie Foundation trustees chairman Scott Hastings.
"We would like to thank the Welsh Rugby Union and Scottish Rugby for this significant and very welcome decision, which will add even more to the financial benefits we are grateful to be receiving from this weekend," former Scotland international Hastings said.
Wales, meanwhile, continued preparations for Saturday's encounter with a public training session at the Principality Stadium on Monday.
A crowd of more than 10,000 watched as the Wales squad went through its paces under the guidance of assistant coaches Edwards, Rob Howley and Robin McBryde.
Head coach Warren Gatland looks set to be back in camp later this week after returning home to New Zealand following the death of his father.
The Wales team will be announced on Thursday, with established names like Alun Wyn Jones, Leigh Halfpenny, George North, Jonathan Davies and Ken Owens all likely to be involved.
Wales are unbeaten against Scotland in Cardiff since 2002 and have won 14 of the last 16 fixtures - home and away - between the countries.