Griffins has reduced the size of its Choc Thins packaging as well as other biscuits - and Kiwis aren't happy.
On Sunday, a Twitter user drew attention to the revelations, and judging by the reaction online, it isn't a popular decision.
One labelled it a "shocking discovery" while another said it was "outrageous".
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"Heck we are being ripped off so much these days," one Twitter user wrote.
Newshub has contacted Griffins for comment, but the business has confirmed the packaging shrink - from 200g to 180g - to Stuff and NZME.
"In light of various operational cost increases, we have recently made a change to our Chocolate Thins, Jaffa Thins, Chit Chats and Chocolate Fingers biscuits packaging," spokesperson Hannah McKee told Stuff.
But one woman said on Twitter she's already stopped buying Choc Thins.
It's not the first time this year a food company sparked outrage. In February, Cadbury reduced its packets of sweets like Jubes, Wine Gums and Jet Planes from 240g to 180g. Mint Imperials also dwindled by 25 percent - from 200g to 150g.
Fruit Bursts, Minties, Milk Bottles, Milk Shakes, Pineapple Lumps, Marshmallows and Eskimos also all shrunk, with the cuts ranging from 22.7 percent to 11.8 percent.
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Prior to that, the confectionery manufacturer attracted major outrage from New Zealanders for shrinking some of its best-loved treats - from its Roses, to its marshmallow Easter eggs, to its family blocks.