California Gov. Jerry Brown has signed a law that will step up enforcement to make sure that vendors who sell in California farmers’ markets grow the commodities they sell.

Signed in late September, AB 1871, puts in place fines and other penalties for false claims by vendors selling at farmers’s markets.

Starting in 2015, the law requires vendors of agricultural products selling at certified farmers’ markets to comply with specified signage and labeling requirements or be subject to fines and penalties. The law requires that a certified farmers’ market producer registers with the California Department of Agriculture by applying for a certificate from a county agricultural commissioner.

The law also puts in a place a $2 per day fee for each farmers’ market vendor, according to the text of the law. Vendors at farmers’ markets must post a sign stating “We Grow What We Sell” and clearly label organic products.