A homeless man with 60 prior arrests was arrested Sunday after allegedly whacking a 6-year-old boy over the head with a laptop in an unprovoked attack in Upper Manhattan, police and sources said.

The victim was with his parents when Michael Johnson, 60, allegedly launched the random attack at the intersection of West 114th Street and Manhattan Avenue at about 2:30 p.m., according to sources and the NYPD.

The youngster was taken to St. Luke’s Hospital to be evaluated, cops said

Johnson was busted and later charged with assault at Manhattan Criminal Court.

The suspect allegedly told police, “Little bastard. I hit him over the head and he can’t prove shi-,” according to a criminal complaint.

He was being held Monday night in lieu of $25,000 bail.

Johnson had an open warrant for criminal mischief for allegedly drawing swastikas.

Sources said the suspect has 60 past arrests and has been hit with charges including burglary, larceny, robbery and assault.