The 135,000 revellers attending this year's could find themselves unable to vote on Referendum Day, which falls on 23 June, as it clashes with the day two of Britain's biggest music festival.
As there will be no polling stations inside the site, Glastonbury organisers have urged people to register to vote, request a postal ballot or apply for someone back home to vote on their behalf instead.
All those finding out this week that they have successfully secured tickets to the popular festival are "strongly encouraged" to ensure they still have a say on the UK's membership of the EU.
Organisers have written in confirmation e-mails to festival-goers this week:
"On Thursday 23 June - the day after Glastonbury's gates open - there will be a referendum on whether Britain should remain in the European Union. There will not be a polling station at the Festival, so we are strongly encouraging our ticket holders to register to vote by post or by proxy.
To take part in the EU referendum you must be registered to vote by Tuesday 7 June. You can register to vote here.
To vote by post, voters in Great Britain need to submit a postal vote application by 5pm, Wed 8 June 2016, while voters in Northern Ireland need to submit a postal vote application by 5pm, Friday 3 June 2016. You can download the form here.
The deadline for applications to vote by proxy in Great Britain is 5pm, Wednesday 15 June. The deadline for applications to vote by proxy in Northern Ireland is 5pm, Friday 3 June 2016. You can download the form here."
Yesterday, it was revealed Jeremy Corbyn would be among those performing at Glastonbury this year.
The Labour leader will appear along with his shadow chancellor, John McDonnell, on the 'LeftField' stage to address adoring fans on scrapping Trident.