Millie Bobby Brown has broken her knee cap.
The 14-year-old star is on crutches and showed off a brace on her leg, but didn't explain how she'd sustained the injury in a video she shared to Instagram.
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The Stranger Things actress has been ordered to "rest up" so her injury means she will be unable to attend the MTV Movie & TV Awards on Monday.
She said in the clip: "Another milestone in my life, I've never actually broken a bone.