Everyone’s favorite ravenous blue puppet took to social media on Monday to add his gravelly voice to a resounding chorus that has grown louder and louder in recent years, decrying one of corporate America’s favorite margin-bumping tricks.

“Me hate shrinkflation!” Cookie Monster shouted into the void on X. “Me cookies are getting smaller.😔”

As prices skyrocketed during the COVID-19 pandemic, companies have tried to figure out how to keep them low without having to eat higher costs. So they passed those costs along by giving consumers less stuff instead.

Here’s what to know about shrinkflation.

What is shrinkflation?

If you saunter over to r/shrinkflation, the 150,000-member subreddit, you can get a quick sense of what’s going on and why it bothers people so much. In one recent post, a Canadian user noticed that a bottle of ranch dressing that went for $2.49 used to be 475 mL. A new bottle for the same price was 425 mL.

Stephen R. Scherger, CFO of the packaging design firm Graphic Packaging Holding Company, told analysts on an earnings call last June that such minor adjustments are a good way of grabbing a little extra revenue for the same amount of stuff from, say, a box of cereal.

“That box, while it may have had 20 ounces in it,” he said, “if it goes to 18, the box doesn’t change.”

How much of an impact is shrinkflation having on prices?

The tricky thing about shrinkflation is that it doesn’t technically change the price of the item. But that’s what people hate about it — when they notice it. Ahead of the Super Bowl last month, President Joe Biden used his bully pulpit to castigate snack and beverage companies for what he suggested was a short-changing of the American consumer.

“As an ice cream lover, what makes me the most angry is that ice cream cartons have actually shrunk in size but not in price” he said. “Give me a break. The American public is tired of being played for suckers.”

Will shrinkflation be permanent?

In the same sense that consumers refused to abide prices rising at persistently high rates — just ask the folks at WD-40 — they won’t let companies keep getting away with smaller boxes forever. And one benefit to shrinkflation being a topic of such focus is that if boxes can get smaller, they can get bigger again, too.

That cereal box that Stephen Scherger was talking about? He added: “They may go back to 20 ounces over time.”