diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index d5b2598075..6d854558d4 100644
--- a/Library/Homebrew/os/mac.rb
+++ b/Library/Homebrew/os/mac.rb
@@ -50,19 +50,25 @@ module OS
       end
     end
 
-    def dev_tools_path
-      @dev_tools_path ||= if tools_in_prefix? CLT::MAVERICKS_PKG_PATH
-        Pathname.new "#{CLT::MAVERICKS_PKG_PATH}/usr/bin"
+    def dev_tools_prefix
+      @dev_tools_prefix ||= if tools_in_prefix? CLT::MAVERICKS_PKG_PATH
+        Pathname.new CLT::MAVERICKS_PKG_PATH
       elsif tools_in_prefix? "/"
         # probably a safe enough assumption (the unix way)
-        Pathname.new "/usr/bin"
+        Pathname.new "/"
       elsif not Xcode.bad_xcode_select_path? and not `/usr/bin/xcrun -find make 2>/dev/null`.empty?
         # Note that the exit status of system "xcrun foo" isn't always accurate
         # Wherever "make" is there are the dev tools.
-        Pathname.new(`/usr/bin/xcrun -find make`.chomp).dirname
+        Pathname.new(`/usr/bin/xcrun -find make`.chomp.sub('/usr/bin/make', ''))
       elsif File.exist? "#{Xcode.prefix}/usr/bin/make"
         # cc stopped existing with Xcode 4.3, there are c89 and c99 options though
-        Pathname.new "#{Xcode.prefix}/usr/bin"
+        Pathname.new Xcode.prefix
+      end
+    end
+
+    def dev_tools_path
+      @dev_tools_path ||= if File.exist? "#{dev_tools_prefix}/usr/bin/make"
+        Pathname.new "#{dev_tools_prefix}/usr/bin"
       end
     end