T-Mobile’s Black Friday discounts were all about Samsung, but the retailer is advertising iPhone deals for Cyber Monday. If you plan to buy an iPhone 6, 5s or 5c on Monday, T-Mobile will give you a memory upgrade for free.

Select a 16GB iPhone 6 and T-Mobile will upgrade it to a 64GB iPhone 6; select a 32GB iPhone 5s and T-Mobile will upgrade it to a 64GB iPhone 5s, select an 8GB iPhone 5c and T-Mobile will upgrade it to a 32GB iPhone 5c.

“Additional memory means more space for the epic photos and videos shot on your iPhone,” T-Mobile said in a press release. “It means enjoying more of the 1.3 million amazing apps available on the App Store and having plenty of room to grow your content libraries as your storage needs grow over time.”

The Cyber Monday deal begins 2:01 a.m. PST (5:01 a.m. EST) and ends 11:59 p.m. PST or while supplies last, and is only available online. Customers must purchase a service plan in addition to an iPhone handset.

T-Mobile has done a lot to promote the iPhone on its network. In June, the carrier announced its Test Drive program, which lets customers on other carriers to “cheat” on their network by trying a T-Mobile powered iPhone handset for one week, free of charge. T-Mobile added the iPhone 6 to the Test Drive program in September.

T-Mobile CEO John Legere said during the network’s third-quarter earnings call in October that the iPhone 6 launch was the carrier’s biggest ever, with the iPhone now accounting for 20 percent of T-Mobile’s smartphone base.