message: Define as prop
diff: @@ -7,7 +7,9 @@ import sx from './sx'
  import theme from './theme'
  import {ComponentProps} from './utils/types'
  -const Position = styled(Box)<SystemPositionProps>`
  +type StyledPositionProps = {as?: React.ElementType} & SystemPositionProps
  +
  +const Position = styled(Box)<StyledPositionProps>`
  ${POSITION};
  ${sx};
  `
  