diff --git a/Library/Homebrew/formula_support.rb b/Library/Homebrew/formula_support.rb
index 77089d42c9f7a96356915bb1ba52964bb3feeed7..6813c1faa247cfbd5a0dbc442c5bf86579ef3b69 100644
--- a/Library/Homebrew/formula_support.rb
+++ b/Library/Homebrew/formula_support.rb
@@ -25,19 +25,19 @@ class KegOnlyReason
   def to_s
     case @reason
     when :provided_by_osx then <<-EOS
-Mac OS X already provides this software and installing another version in
+OS X already provides this software and installing another version in
 parallel can cause all kinds of trouble.
 
 #{@explanation}
 EOS
     when :shadowed_by_osx then <<-EOS
-Mac OS X provides similar software, and installing this software in
+OS X provides similar software, and installing this software in
 parallel can cause all kinds of trouble.
 
 #{@explanation}
 EOS
     when :provided_pre_mountain_lion then <<-EOS
-Mac OS X already provides this software in versions before Mountain Lion.
+OS X already provides this software in versions before Mountain Lion.
 
 #{@explanation}
 EOS
diff --git a/Library/Homebrew/global.rb b/Library/Homebrew/global.rb
index 7374bd5e833becbc1941ec5f0c6a93976d770a51..2c71b473f41d81f2c5ef4bd3835e7778c262459a 100644
--- a/Library/Homebrew/global.rb
+++ b/Library/Homebrew/global.rb
@@ -30,7 +30,7 @@ RUBY_BIN = RUBY_PATH.dirname
 if RUBY_PLATFORM =~ /darwin/
   MACOS_FULL_VERSION = `/usr/bin/sw_vers -productVersion`.chomp
   MACOS_VERSION = MACOS_FULL_VERSION[/10\.\d+/]
-  OS_VERSION = "Mac OS X #{MACOS_FULL_VERSION}"
+  OS_VERSION = "OS X #{MACOS_FULL_VERSION}"
 else
   MACOS_FULL_VERSION = MACOS_VERSION = "0"
   OS_VERSION = RUBY_PLATFORM
diff --git a/Library/Homebrew/os/mac/xcode.rb b/Library/Homebrew/os/mac/xcode.rb
index 1ae0a57d680d6f83452e7dae59ad89e74fb03667..ac8609f2310c642b5b0c5a04e01012a0571d3144 100644
--- a/Library/Homebrew/os/mac/xcode.rb
+++ b/Library/Homebrew/os/mac/xcode.rb
@@ -20,7 +20,7 @@ module OS
           if MacOS.version > "10.10"
             "7.0"
           else
-            raise "Mac OS X '#{MacOS.version}' is invalid"
+            raise "OS X '#{MacOS.version}' is invalid"
           end
         end
       end