Josh Gad thinks the early screenings of 'Frozen' were ''a mess''.

The 39-year-old actor voices snowman Olaf in the Disney series, which has proved to be a massive hit, but Josh revealed that the project got off to a rocky start.

Speaking on PeopleTV's 'Couch Surfing', he explained: ''I'll never forget, six or seven months prior to the movie coming out, I was with (songwriter) Bobby Lopez ... so I said, 'How's the movie coming?' and he goes, 'Well, we just screened the movie and it's a mess.'''

The 'Artemis Fowl' star recalled asking Lopez if the project could be rescued, when he was informed that 'Do You Want to Build a Snowman?' was being introduced into the 2013 movie.

He was told by Bobby: ''I hope so. Yeah, we're playing around with this idea now, like we need this moment where we really see the girls' affection for each other early.

''So we're playing with this song, that's called 'Do You Want to Build a Snowman?'''

However, Josh knew 'Frozen' would be a success when his wife, Ida Darvish, described it as ''special''.

Josh recalled: ''Cut to six months later, I'm with my wife and we're screening it with Kristen Bell (who voices Anna) and Idina Menzel (Elsa) and the creatives.

''I turned to my wife - who's the most critical person I know - and she looks at me and she goes, 'This is really special, this is really, really special' and I left it there being like, 'OK we hit the mark'''.

Josh previously said he doesn't feel Olaf should get a spin-off movie as it would ''separate'' the loveable snowman from the other characters.

Asked about the possibility, he said: ''Probably not. And I'll tell you why.

''I feel like Olaf really is a part of the fabric of the actual stories that include Anna, Elsa, Kristoff, etc.

''And to me, separating him from that group doesn't necessarily feel warranted and doesn't necessarily feel earned.''