Add Nick Cannon to the growing list of people who are concerned about Amanda Bynes’ erratic behavior.

The star, 32, told Howard Stern in an on-air interview that he has tried to reach out to Amanda, with no success.

Cannon, who is married to Mariah Carey, worked with Bynes, 27, when he appeared on the show All That from 1998-2000. Bynes starred on the show from 1996-2002.

“I worked on Amanda’s show…that’s like my little sister,” Nick said after Stern brought up the subject of the erratic actress.