The Irish film star, 33, has been in Hollywood so long he worries his Irish accent no longer sounds real.

“That kind of accent can be very lyrical and I’ve been out of Ireland for a while – that’s my excuse,” he said, according to a music and showbiz website.

“I hope I don’t sound like an American doing an Irish one, that’d be the worst.”

In his new film, “Ondine,” Farrell plays a fisherman called Syracuse who falls in love with a mermaid. Alicja Bachleda-Curus, who plays the mermaid, became Farrell’s partner and the mother of his son, following the filming.

Although he returns to Ireland regularly to visit his family in Dublin, Farrell is based in LA where he lives with Bachleda-Curus.

“Ondine” was filmed in Castletownbere in County Cork, Ireland. It is the creation of renowned Irish film-maker Neil Jordan, whose work includes classics like “The Crying Game” and “Michael Collins.”

One review, on Variety.com, finds the Irish accents notable. “Some of the thicker Irish accents will pose a problem for auds in the US and elsewhere,” the review states.