README in mkmf-lite-0.2.3 vs README in mkmf-lite-0.2.4

@@ -9,10 +9,10 @@
 
 == Synopsis
   require 'mkmf/lite'
 
   class System
-    include Mkmf::Lite
+    extend Mkmf::Lite
 
     HAVE_PW_NAME = have_struct_member('struct passwd', 'pw_name', 'pwd.h')
 
     def some_method
       if HAVE_PW_NAME