diff --git a/docs/reference/ImageGrab.rst b/docs/reference/ImageGrab.rst
index 0b94032d5..5c365132f 100644
--- a/docs/reference/ImageGrab.rst
+++ b/docs/reference/ImageGrab.rst
@@ -22,7 +22,10 @@ or the clipboard to a PIL image memory.
     .. versionadded:: 1.1.3 (Windows), 3.0.0 (macOS), 7.1.0 (Linux)
 
     :param bbox: What region to copy. Default is the entire screen.
-                 Note that on Windows OS, the top-left point may be negative if ``all_screens=True`` is used.
+                 On macOS, this is not increased to 2x for retina screens, so the full
+                 width of a retina screen would be 1440, not 2880.
+                 On Windows OS, the top-left point may be negative if
+                 ``all_screens=True`` is used.
     :param include_layered_windows: Includes layered windows. Windows OS only.
 
         .. versionadded:: 6.1.0