Chipotle offering free guac for National Avocado Day

It's only appropriate to celebrate National Avocado Day with free guacamole.

Chipotle Mexican Grill is offering that deal on the national holiday, which falls on Tuesday, July 31. It's usually an extra cost for the popular side, but on Tuesday, it'll be a gift.

Customers will have to order an entree, online or in the Chipotle app. It is not available for in-store purchases.

To redeem it, you must log into their Chipotle accounts, or create one. After selecting the entree, you can add the side of guacamole as an add-on, side items or as a regular order of chips and guacamole. Before checking out, enter the coupon code, "AVOCADO."

"Our fresh, homemade guacamole has a massive fan following," said Chris Brandt, chief marketing officer at Chipotle in a press release. "We want to show our love for the avocado and reward our customers' guac obsession. Plus, it's a major bonus that you can skip the line when you order ahead with our app or at chipotle.com."