Jennifer Aniston showed off some new, longer locks at Portia DeRossi's 41st birthday party Friday night at LA hotspot Crossroads.

A private party thrown at the hip vegan restaurant by wife Ellen DeGeneres, the group included only close friends like Aniston, who's been pals with the couple for ages.

Aniston chopped her hair into a cropped 'do back in November and X17online had the EXCLUSIVE pix. We spotted Jen as recently as two weeks ago at the skin salon, still sporting above-the-shoulder locks.

But it seems the woman with the most famous hair in the world, wanted her longer look back and had her hairstylist BFF Chris McMillan add in some extensions ... check out the evidence:

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