Telegram Messenger will be able to make audio calls and change themes in the future, CEO Pavel Durov recently said on Twitter.

Customizable themes were made for Telegram on desktop last week.

VentureBeat reached out to the messaging app on Monday to ask when audio calls will be available, but a Telegram spokesperson declined to comment beyond Pavel’s tweet.

Telegram said in April 2015 that it had developed “encrypted voice calling technology some time ago,” but never prioritized the technology. It’s not yet clear if Telegram’s future audio calls will be encrypted, but security is a hallmark feature of the chat app.

Telegram’s encryption was called into question last week when the messaging app appeared in unverified accounts that the Russian government has been “cultivating, supporting, and assisting” President-Elect Donald Trump for years.

According to the dossier published by BuzzFeed and compiled by former MI6 spy Christopher Steele, the Russian FSB security agency has infiltrated Telegram and “successfully cracked the communications software and therefore it was no longer secure to use.”

Telegram told The Verge that Steele’s report is likely fake, and that the dossier may have referenced a vulnerability in SMS login requests discovered last spring.

Members of the intelligence community have verified Steele to be a reputable spy, but at least one claim of contact between Russian officials and a member of a Trump campaign has been proven false.

Bots and artificial intelligence have seen a surge in interest lately, but so has calling on some of the largest chat platforms on the planet. Since last November, Facebook Messenger, WhatsApp, Slack, WeChat, and Kik added audio or video call capabilities.