Theresa May has replaced her Blackberry mobile device with an iPhone.
The prime minister had been the "last member of the No 10 team" still using a Blackberry handset, news site Politico reported.
The Canadian company behind Blackberry stopped making smartphones itself in 2016, following a steep decline in sales, and licensed other companies to make devices in its name.
For security reasons, Mrs May's new iPhone is unlikely to have many apps.
The decision is a further signal of how the reputation of the Blackberry handset, once considered one of the world's most secure mobile devices, has changed.
"Blackberry, once the champion of the workplace, has very much become a niche player with strong competitors on all sides," said Stuart Miles, founder of gadget review site Pocket-lint.
"It isn't completely washed up yet - but it's had its powerful moment in the sun. I'm not sure it will ever rise to be the trailblazer it once was."
Of Mrs May's decision, he added: "It's hard to change, but sometimes you have to embrace a new world."
In 2013, US President Barack Obama revealed he was not allowed to have an iPhone, for security reasons, but was able to keep his Blackberry.
And in January 2017 President Donald Trump reportedly had to give up his Android phone on the advice of US security agencies.