UIScrollView does not enlarge UIView after applying affine transform to last

I have been struggling with these problems since two days and have not found a solution yet. My setup is pretty simple: I have a UIScrollView, a UIView inside it, return the latter in viewForZoomingInScrollView and there really is nothing else. In fact, it works as expected. The problem comes when I add this line to the viewDidLoad of my view controller:

viewForZooming.transform = CGAffineTransformMakeRotation(M_PI/2); 

      

        
        
        
      

    

Then the scroll view no longer zooms in. Is it because the frame becomes invalid after the view is converted? Is there a workaround?

Thank.