Koch planned his own funeral in great detail, but when it came to engraving the tombstone, well, he had to leave that to someone else.
And they got it wrong.
The tombstone says Koch was born in 1942, but he was actually born in 1924, 18 years earlier.
The engraver, Tommy Flynn, of Flynn Funeral and Cremation Memorial Services, says it was "an inadvertent error" and that he feels "terrible." He says he'll correct it.
Koch was buried in Trinity Church cemetery in Washington Heights after dying of congestive heart failure in February at 88.
The Democratic mayor is credited with helping save New York from its economic crisis in the 1970s and leading it to financial rebirth.