I have drawn a rounded rectangle with corner radius by UIBezierPath with init(roundedRect:byRoundingCorners:cornerRadii:) But I found that when corner radius is more than about 33% of the rectangle's width or height then corner radius are drawn by 50% of rectangle's width or height. Is this an iOS bug or Did I just do something wrong? I just want the corner radius is the same with the value when the corner radius is less than 50% of the rectangle's width or height. Example Code final class CornerView: UIView { override func draw(_ rect: CGRect) { let rect = CGRect(x: 100, y: 100, width: 100, height: 100) let roundedPath0 = UIBezierPath( roundedRect: rect, byRoundingCorners: [.allCorners], cornerRadii: CGSize(width: 20, height: 20)) UIColor.black.setFill() roundedPath0.fill() let roundedPath1 = UIBezierPath( roundedRect: rect, byRoundingCorners: [.allCorners], cornerRadii: CGSize(width: 25, height: 25)) UIColor.green.setFill() roundedPath1.fill() let roundedPath2 = UIBezierPath( roundedRect: rect, byRoundingCorners: [.allCorners], cornerRadii: CGSize(width: 30, height: 30)) UIColor.blue.setFill() roundedPath2.fill() let roundedPath3 = UIBezierPath( roundedRect: rect, byRoundingCorners: [.allCorners], cornerRadii: CGSize(width: 35, height: 35)) UIColor.red.setFill() roundedPath3.fill() } } Result The red rectangle should be drawn in the same corner radius ratio with the below rectangles. I'm using Xcode Version 13.4.1 (13F100) iOS Simulator: iOS 15.5 iPhone 8 Plus