Error on Sass Interpolation #{} inside @keyframes

I'm getting an error when using Interpolation inside a loop that generates @keyframes.

 300:1  error  Please check validity of the block starting from line #300  Fatal

It doesn't happen in cases when @keyframes are inside the @for loop, it only seems to happen when there is a @for loop inside the @keyframes.

$n-titles: 5;
$angle: 360deg / $n-titles;

@keyframes switcher3d {
  @for $i from 0 to ($n-titles + 1) {
    #{$i * 100 / $n-titles}% {
      transform: rotateY($i * $angle);
    }
  }
}

Should this be written in a different way?