Ibiza's reputation as Europe's top destination for the UK's young revellers is at risk as visitors are getting older, new figures show.
Travel agent Thomas Cook reported that millennials are moving away from the Spanish island in favour of more affordable clubbing experiences in Greece.
Over the past five years, one in six bookings have shifted from those under 30 to those aged 30-39, the firm said.
Many of Ibiza's former ravers are still making their annual pilgrimage to the White Isle, but are now in their 30s with more spending money and changing tastes.
This has led to a rise in demand for wellness sessions in the day, VIP party experiences at night and designer hotels, according to Thomas Cook.
The travel agent has also seen a 6% increase in family holidays to Ibiza as the island's regulars move into the next phase of their life.
Tony Hopkins, Thomas Cook's UK product director, told the Press Association: "Ibiza is changing as its customers' tastes change.
"The happy hardcore of the 90s and early 2000s is giving way to chillout beats to suit a growing band of thirty-somethings and their young families.
"It's always been a cool destination and it's now getting more exclusive.
"The hotels on the island have invested wisely in their offer to customers which have kept customers coming back as their tastes and priorities change."
Meanwhile, Greek islands which previously had a reputation for quiet breaks are proving popular with young revellers.
Thomas Cook has seen bookings for Kos and Zante double for people aged under 25 since 2009, while demand from those over 50 has declined.
Visitors can party into the early hours on Bar Street in Kardamena, Kos, while Zante's Laganas Strip is one of Europe's most popular nightlife hotspots for holidaymakers on a tight budget.
Mr Hopkins said: "Kos and Zante's dedicated party areas are attractive to young revellers looking for a more affordable alternative to Ibiza.
"Greece is having a bumper year and these emerging party islands just help to broaden Greece's offer even more, while customers looking for the Mamma Mia experience have a huge range of authentic Greek hotels and restaurants across its thousands of islands."