diff --git macosx/README macosx/README
index d7333e851..3189f2a85 100644
--- macosx/README
+++ macosx/README
@@ -190,7 +190,7 @@ which can be used to get or set the tabbingIdentifier for the NSWindow
 associated with a Tk Window.  See section 3 for details.
 
 - The command:
-  tk::unsupported::MacWindowStyle appearance window ?newAappearance?
+  tk::unsupported::MacWindowStyle appearance window ?newAppearance?
 is available when Tk is built and run on macOS 10.14 (Mojave) or later.  In
 that case the Ttk widgets all support the "Dark Mode" appearance which was
 introduced in 10.14. The command accepts the following values for the optional
