Marmite lovers who haven't been able to buy larger jars of the spread during lockdown can blame the coronavirus.
Unilever, which owns the brand, says it has temporarily stopped producing all pack sizes other than its 250g jar, prompting a flurry of complaints on social media.
The firm blamed surging demand and a shortage of brewer's yeast, a key ingredient.
But it promised that normal supply would resume soon.
Hi Tim, due to brewers yeast being in short supply (one of the main ingredients in Marmite) Supplies of Marmite have been affected.— Marmite (@marmite) June 10, 2020
As a temporary measure we have stopped production of all sizes apart from our 250g size jar which is available in most major retailers.
Fans of the spread, which is famous for dividing opinion, took to Twitter to vent their dismay at the shortage.
"I need Marmite like oxygen and really need more 400g squeezy jars. Can you advise on which retailers stock those at the moment? Thank you," tweeted Tim Robey.
Another quipped: "I've just turned the news on to hear of a Marmite shortage - just when we thought 2020 couldn't get any worse."
Oh @marmite why can’t I find a squeezey jar anywhere?! Tried my local Tesco and sainsburys and nothing!! Is there a shortage I should know about?! 😭😭— Lauren Vangeen (@lollylash) May 27, 2020
Yeast by-product, generated when brewers make beer, is a key ingredient in Marmite. However, with pubs having been closed since March to battle Covid-19, there has been a shortage of late.
At the same time, Unilever said that more people preparing meals at home during lockdown had caused a surge in demand for the spread.
As a result, it said its factory in Burton-on-Trent had temporarily limited supply, although production levels are now back to normal.
"With these issues now resolved, we are continuing to make Marmite as normal again, which means that the full range of jars should be back on supermarket shelves very shortly," a spokeswoman told the BBC.