diff --git a/shell/browser/native_window_mac.mm b/shell/browser/native_window_mac.mm
index 89b27b3416..87311853eb 100644
--- a/shell/browser/native_window_mac.mm
+++ b/shell/browser/native_window_mac.mm
@@ -1298,7 +1298,12 @@ void NativeWindowMac::SetVibrancy(const std::string& type) {
     const bool no_rounded_corner =
         [window_ styleMask] & NSWindowStyleMaskFullSizeContentView;
     if (!has_frame() && !is_modal() && !no_rounded_corner) {
-      CGFloat radius = 5.0f;  // default corner radius
+      CGFloat radius;
+      if (@available(macOS 11.0, *)) {
+        radius = 9.0f;
+      } else {
+        radius = 5.0f;  // smaller corner radius on older versions
+      }
       CGFloat dimension = 2 * radius + 1;
       NSSize size = NSMakeSize(dimension, dimension);
       NSImage* maskImage = [NSImage imageWithSize:size