A fired Brooklyn building superintendent was so angry over getting the boot that he strangled the man who replaced him — then buried the body in his grandmother’s back yard, authorities say.

Ex-super Keith Floyd, 40, already a predicate felon, was held without bail Thursday for allegedly killing the man who took his Bushwick job.

Victim Daniel Rivera had been missing since Sept. 22; his body was recovered Oct. 6, officials said Thursday. It took another nine months for prosecutors to build their case.

Prosecutors have also charged Floyd’s sister, Adrianna, with helping him move the body from place to place before it was found covered with dirt behind 54 Himrod St.

Floyd was angry that the victim “took his job,” Assistant District Attorney Wilfredo Cotto told a judge Thursday in asking successfully that the accused murderer be held without bail. “He kills the decedent, then transports his body and buries it in his grandmother’s back yard.”

At the time, Floyd was on probation until 2022 — it was not immediately clear what for.

Defense lawyer Bernard Udell countered that the case is baseless.

“There’s very little in the way of evidence here that he did anything at all,” Udell told the judge.