Kourtney Kardashian took her younger sister Kim Kardashian out for a pre-birthday celebration at a nail salon in New York City yesterday (Thu. Oct 20), and both ladies were rocking styles inspired from the 1970’s.

Kim stepped out of the NYC nail salon after her birthday mani-padi in a pair of eggplant colored high-waisted pants paired with a light pink top and a navajo print headband, while big sis Kourtney rocked a purple printed floor-length dress that she accessorized with big earrings.

Kim Kardashian turns 31 years old today. Her sister Kourtney tweeted:

“Happy birthday to my favorite sister of the day @KimKardashian! Let’s party like it’s 1980!”

Happy Birthday Kim!

More pics of Kourtney and Kim leaving the nail salon are below: