All major retailers have now agreed to join the grocery code of conduct.
Walmart and Costco have now come on board, federal officials announced Thursday.
They are joining Loblaw, Sobeys and Metro as part of the industry-led code.
“This is a positive step towards bringing more fairness, transparency, and predictability to Canada’s grocery supply chain and for consumers,” said a statement from Agriculture and Agri-Food Canada.
The code is meant to help level the playing field, particularly for small independent grocers.
Statistics Canada said grocery prices have increased nearly 22 per cent over the past three years.