Amazon and Walmart are in war over worker pay — and now corporate taxes.

After Amazon Chief Executive Officer Jeff Bezos on Thursday issued a challenge to other retailers, not naming which ones specifically, to match Amazon’s pay and benefits, Walmart snapped right back.

“Today I challenge our top retail competitors (you know who you are!) to match our employee benefits and our $15 minimum wage. Do it! Better yet, go to $16 and throw the gauntlet back at us. It’s a kind of competition that will benefit everyone,” Bezos wrote in his annual letter to shareholders.

Hey retail competitors out there (you know who you are 😉) how about paying your taxes? https://t.co/Rmh3VZOHsG @JeffBezos — Dan Bartlett (@danbartlett6) April 11, 2019

“Hey retail competitors out there (you know who you are) how about paying your taxes?” tweeted Walmart’s Executive Vice President of Corporate Affairs Dan Bartlett on Thursday morning, sharing an article about Amazon paying $0 in federal taxes on more than $11 billion in profits last year.

A representative from Amazon wasn’t immediately able to comment on Bartlett’s tweet.

Walmart’s minimum wage of $11 an hour, set in January 2018, is still below Amazon’s, which was hiked to $15 in November. But Walmart has said its average worker earns $17.55 an hour with wages and benefits.

As for Bartlett’s argument: Amazon's low tax bill mainly stemmed from the Republican tax cuts of 2017, carryforward losses from years when the company was not profitable, tax credits for massive investments in R&D, and stock-based employee compensation.