For the first time in its 256-year history, Guinness is set to become vegan-friendly.
The company has previously used isinglass - a byproduct created from fish bladders - in order to filter extra yeast from its stout.
But a Guinness spokesperson told The Times they are aiming to replace this method with a new filtration plant next year.
"Whilst isinglass is a very effective means of clarification, and has been used for many years, we expect to stop using it as the new filtration asset is introduced," the spokesperson said.
The use of isinglass does not affect the flavour or texture of a beer, it just helps the sediment to settle more quickly.
However, The Times' report states that tiny particles of fish do remain in the final drink.
Guinness' decision to scrap the method will be popular with vegans and vegetarians who have campaigned for the company to stop using isinglass in the past.
A previous Change.org petition on the topic, which was signed by almost 2,000 people, read: "If Guinness were to become openly veggie-friendly it would not only help raise awareness of isinglass, but would also elevate Guinness's brand perception and popularity above other beverages.
"The world's vegetarian population is rising and it is increasingly important that brands recognise and adapt to this growing section of the market, especially if they can do so without upsetting meat-eaters or changing their end product."
The new method for filtering Guinness will be rolled out across the company during 2016.