The latest edition of the phone book in Dublin has been printed and distributed with an error each time the Irish fada appears.
Golden Pages, which prints the book on behalf of eircom, said a "technical fault" had occurred after the proofing stage and during the printing process. It said the result was a corrupt character appeared each time a letter with a fada over it was printed.
The company said in a statement it "sincerely regrets any inconvenience caused by this error" and said a supplement containing all of the corrected listings has been prepared and is being distributed.
It added that "immediate steps" had been taken to prevent the error happening again. Irish language listings in all other areas of the State were unaffected by the error.
Sinn Féin TD Aengus Ó Snodaigh, who first highlighted the error, said: "People with Irish names will be disappointed that all other languages in the directory appear to be OK but our own native language has been neglected.
"The Government should recall all these directories, have the problem sorted, re-print it and re-distribute it.
"If that is not feasible at the very least they should give a commitment not to ever let this happen again."
