diff --git a/Library/Homebrew/macos.rb b/Library/Homebrew/macos.rb
index 13f940cecd..a58f980b04 100644
--- a/Library/Homebrew/macos.rb
+++ b/Library/Homebrew/macos.rb
@@ -74,7 +74,7 @@ module MacOS extend self
       # Xcode.prefix is pretty smart, so lets look inside to find the sdk
       opts << "#{Xcode.prefix}/Platforms/MacOSX.platform/Developer/SDKs/MacOSX#{v}.sdk"
       # Xcode < 4.3 style
-      opts << "/Developer/SDKs/MacOS#{v}.sdk"
+      opts << "/Developer/SDKs/MacOSX#{v}.sdk"
       opts.map{|a| Pathname.new(a) }.detect { |p| p.directory? }
     end
   end