iOS warning message : Incompatible pointer types passing 'CGFloat *' (aka 'double *') to parameter of type 'float *'

This is causing my App to act up. this error is happening on this line modff(floatIndex, &intIndex); What do I need to do to fix this issue?

Edit: it is because of &intIndex

- (BOOL)isFloatIndexBetween:(CGFloat)floatIndex {
  CGFloat intIndex, restIndex;
  restIndex = modff(floatIndex, &intIndex);
   BOOL isBetween = fabsf(restIndex - 0.5f) < EPSILON;
  return isBetween;
  }