Safeway (NYSE:SWY) supermarkets will soon offer its own branded coffees in single-serving containers designed to fit the popular Keurig coffee brewing machine from Green Mountain Coffee Roasters (NASDAQ:GMCR).

The supermarket will offer five varieties of its coffees in K-Cup containers. They’ll join its existing line of instant K-Cups drinks, launched in January, which include two cappuccinos and a hot cocoa drink, Reuters noted.

Safeway’s announcement comes just days after Kroger‘s (NYSE:KR) said it plans to offer its branded coffees in K-Cups.

The supermarkets join Starbucks (NASDAQ:SBUX), Kraft (NYSE:KFT), Sara Lee (NYSE:SLE) and Nestle (PINK:NSRGY) in offering coffee in K-Cups. The growing market for K-Cup packaged coffees may ultimately hurt Green Mountain’s sales because supermarket brands are priced well below Green Mountain-branded K-Cups.

Making the Keurig-compatible containers for Safeway is Rogers Family, a California-based manufacturer that doesn’t have a licensing agreement with Green Mountain and has been sued by the coffee maker for patent infringement. Rogers contends that design differences in its Keurig-compatible containers avoid infringing on Green Mountain’s patents.

Shares of both Safeway and Green Mountain Coffee Roasters slipped more than 1% in Friday midday trading.