A man who lured two children from a North Perth childcare centre and sexually assaulted them has had two years added to his prison term for separately abusing a boy.

Vincenzo Mule, 54, was found guilty by a jury of two counts of indecent dealing with a child and two counts of sexual penetration of a child, committed against a six-year-old boy he knew.

Mule was sentenced in the WA District Court on Monday and has now been sentenced to a total of 16-and-a-half years in prison for the sexual offending and a separate arson offence.

AAP