diff --git a/README.md b/README.md
index 9e8a8ef..e6cdfd0 100644
--- a/README.md
+++ b/README.md
@@ -37,13 +37,13 @@ MacVim.
 
 How do you do it?
 
-#### OSX 10.9 (Mavericks)
+#### OS X 10.9 (Mavericks)
 
 If you are using [`b26abd0` of boxen-web](https://github.com/boxen/boxen-web/commit/b26abd0d681129eba0b5f46ed43110d873d8fdc2)
 or newer, it will be automatically installed as part of Boxen.
 Otherwise, follow instructions below.
 
-#### OSX < 10.9
+#### OS X < 10.9
 
 1. Install Xcode from the Mac App Store.
 1. Open Xcode.