Maisie Williams Wishes Sophie Turner a Happy 21st Birthday With Amazing Throwback Snap -- See the Pic!

Nothing can stop the love fest between these 'Games of Thrones' co-stars.

Happy birthday to Sophie Turner!

The actress turned 21 years old on Tuesday, and her Game of Thrones co-star-turned-BFF Maisie Williams couldn't help but celebrate with an amazing throwback pic from the beginning of their friendship.

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"Happy 21st Birthday @SophieT," Williams wrote on Twitter, alongside an epic pic of the two from years earlier. "Forever looking up to you, in more ways than one."

Williams wasn't the only one spreading the love. Turner quickly took to the app to share a sweet note to her TV sister.

"@Maisie_Williams nah. Lookin up to you, kid," she wrote. "Love you."

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Turner and Williams' love for each other isn't just displayed online -- it's written in ink.

ET caught up with Turner at the Emmys in September, where she opened up about her and Williams' matching tattoos: the date that they both found out they won roles in Game of Thrones.

See more in the video below.