John Oliver’s Last Week Tonight premieres this Sunday on HBO, and to promote the premiere he returned to his roots at Jon Stewart’s Daily Show.

After making a surprise appearance during a skit in which he was outraged to find Stewart’s correspondents faking their nationalities (one of which was Oliver’s replacement), the former reporter sat down with Stewart to talk about the advantages of HBO.

The benefit they had the biggest fun with, while sipping some tea, is the fact that HBO does not censor any words like they do on Comedy Central because the latter is on basic cable.

As noted during the brief interview, Oliver left The Daily Show four months ago to prepare for his new HBO program. As you can see from the below trailer for Last Week Tonight, Oliver’s sense of humor should be carried over to the new show:

Oliver’s first guest for his premiere episode is retired Gen. Keith Alexander. It is his first interview since he retired as Director of the National Security Agency and head of U.S. Cyber Command.

Earlier this week another Daily Show alum, Stephen Colbert, made a surprise appearance on the show.