Chrissy Teigen's son has "graduated" from wearing a helmet.

Miles in his helmet (c) Instagram

Miles in his helmet (c) Instagram

The 'Lip Sync Battle' star revealed in December that nine-month-old Miles - her second child with husband John Legend - needed the headwear to correct his "adorable misshapen head" and she's now shared the happy news that the tot doesn't have to wear it any more.

She wrote on Twitter: "such a trooper for 3 months of helmet. happy graduation, Miles!! (sic)"

Chrissy also posted a video of herself and Miles snuggling on the couch as she wished him a "happy helmet free day".

The baby seemed delighted as the brunette beauty - who also has two-year-old Luna with John - repeated: "No more helmet. No more helmet!"

The 33-year-old star went on to praise the "amazing" process that had helped Miles' head.

She wrote: "they [helmets] get shaved and shaped down every week, depending on how much the child's head is morphing. it's amazing! (sic)"

Chrissy previously told her fans not to "feel bad" when they saw pictures of Miles with his helmet on.

She wrote on twitter alongside a photo of her son with his new headgear: "baby miles getting fitted for a little helmet today for his adorable slightly misshapen head. so if you see pictures, don't feel bad for him because he's just fixing his flat and honestly he's probably gonna be even cuter with it somehow (sic)"

While Miles was wearing a white helmet in the photo, Chrissy vowed to get a number of different ones so he can co-ordinate with his outfits.

She posted in the comments of her Instagram account: "I'm gonna get SO many designs."