This week, the two leaders met in person, kicking off a significant summit between the nations and marking the first face-to-face encounter between a U.S. president and a leader of North Korea. As they spoke, they probably checked emails, texts and made phone calls on something like an iPhone, according to research from U.S. cybersecurity firm Recorded Future.

“Our analysis reveals the overwhelming presence of American hardware and software on North Korean networks and in daily use by senior North Korean leaders,” the report says. Most North Koreans, by contrast, only have access to a limited number of sites using state-sanctioned tools —though the design of those tools is often distinctly Mac-like.

In particular, Kim Jong Un himself seems to be an avid Apple (AAPL) user. The leader has been photographed several times using devices from the tech giant, here with an iMac and here with a MacBook Pro. That’s particularly notable considering the wealth of electronics now coming out of China, North Korea’s largest trading partner.

The profusion of American products comes despite strict sanctions. And for some security experts, it has raised alarm bells that U.S.-made technology could be being used in North Korea’s cyber-espionage activities. While some electronics are likely smuggled, hundreds of thousands have been exported legally in previous years. Those exports reached a peak in 2014, when the U.S. sold $215,862 worth of computers and electronic products to North Korea, according to Recorded Future, which also said that many of the devices it detected in the country are older models or are running older software.

Now, it looks like Kim may get that software update after all. As of Tuesday afternoon in Singapore, the two leaders said they had decided to “leave the past behind,” and signed what they called a “comprehensive document.” The agreement, according to Trump, will put North Korea on a path to denuclearization “very quickly.” In exchange, the U.S. could loosen its sanctions —maybe even on iPhones.