Tower of London and Hampton Court Palace employees have ended strike action and accepted the revised pension offer.
Members of the GMB union working for Historical Royal Palaces (HRP) voted to accept the revised offer that was presented to them following two days of strike action.
The offer confirms the closure of the defined benefit scheme, but in a statement, GMB said members had gained "significant improvements to the defined contribution scheme".
The improvements made as a result of the offer will be available for both GMB members and all other existing HRP defined contribution scheme members.
Michael Ainsley, GMB regional organiser, said: "We are disappointed not to have prevented the closure of the defined benefit pension scheme, however our members have voted to accept this new offer which is considerably better than what was originally on the table.
"Our members can be proud that they stood up and fought hard."
Beefeaters, Jewel House Wardens and other Historic Royal Palaces (HRP) staff were balloted on strike action over the closure of their DB pension scheme in November last year.
While the scheme had already closed to new entrants in 2002, the scheme announced its intention to close the final salary scheme to future accrual as of April 2019, prompting member backlash.
At the end of March 2018, the scheme had a deficit of £4.9m.
Jenny Turton is a freelance journalist