He wants to see Newcastle United tighten up at the back.
The Magpies continued their pre-season preparations by beating Southend United 2-0 at Roots Hall last night, with Vurnon Anita and Yoann Gouffran finding the net.
But there were a number of self-inflicted hairy moments for Newcastle as Benitez's side survived a few scares against Phil Brown's outfit last night.
Benitez's troops are odds-on favourites to win the Championship this season and secure an immediate return to the Premier League in the process.
But the former Liverpool and Real Madrid boss has acknowledged the need to be a little bit stronger at the back if they want to win promotion.
"We conceded maybe one or two chances, not too many. Again, I would say in the Championship you have to concede even less," he said via the Shields Gazette.
Benitez has signed a number of defenders this summer, including Jesus Gamez, Grant Hanley and Isaac Hayden, although the latter could be used in midfield by the Spaniard.
They kick off their Championship season with a trip to Fulham on August 5.