I guess we never truly realised how much One Direction fans cared about Harry Styles hair until this week, when the singer revealed that he's lopped it all off ahead of his appearance in Christopher Nolan's upcoming war drama 'Dunkirk'. Needless to say, they are definitely not happy about it.

Harry StylesHarry changes his 'Style'

Fans today are mourning the death of an important member of One Direction; Harry Styles' hair. The popstar posted a picture on Instagram of himself clutching a disembodied ponytail with the caption 'Whoops'. One positive thing has come out of it though, despite the frantic protestations of his 17.1 million followers, he's donated his locks to The Little Princess Trust which is a charity set up to provide wigs for children who've lost their own hair during cancer treatment.

Indeed, this token of generosity isn't actually the reason for the drastic image change. He's set to make his acting debut in the World War II drama 'Dunkirk', in which he stars opposite Tom Hardy and Cillian Murphy, and so it was likely a necessary move for his as-yet-unknown character.

More: Are One Direction extending their hiatus?

Never fear though, it seems Styles is planning to get his mop back once filming's over. 'Harry's been telling pals that he will grow his hair long again after he's done filming', a source told Hollywood Life. 'It was just the fact that he needed to do it for his film role that he chopped his hair, but he won't be cutting it for a while again after this.'

As much as fans are nursing broken hearts today, we don't actually know what Styles looks like with his long locks yet; maybe they'll like the new look. But then you can't expect miracles.

'Dunkirk' is set to hit theatres in July 2017.

Whoops. #Littleprincesstrust

A photo posted by @harrystyles on