Unable to compare histograms

I'm trying to use teh compareHist function but always get
the error:
Mat::CompareHist - OpenCV Error: (H1.type() == H2.type() && H1.depth() == CV_32F

I've tried changing it with:
grayHist.convertTo(cv.CV_32F, 0, 1);

but after grayHist.depth is still set to 6 ( which is cv.CV_64F) insead of 5 (cv.CV_32F);

Here is my complete code:
`
const img = cv.imread('../Materials/Nike - App Screenshots/mine/nike_running3.PNG');

var grayImg = img.bgrToGray();
var grayHist = cv.calcHist(grayImg, getHistAxis(0));
grayHist.convertTo(cv.CV_32F, 0, 1);
grayHist.normalize( 1, 0, cv.NORM_MINMAX, -1) ;
grayHist.compareHist(grayHist, cv.HISTCMP_CORREL);
`