ext/utf8/ext.h in utf8-0.1.2 vs ext/utf8/ext.h in utf8-0.1.3

@@ -1,7 +1,12 @@
 #ifndef UTF8_EXT_H
 #define UTF8_EXT_H
 
+// tell rbx not to use it's caching compat layer
+// by doing this we're making a promize to RBX that
+// we'll never modify the pointers we get back from RSTRING_PTR
+#define RSTRING_NOT_MODIFIED
+
 #include <ruby.h>
 
 #ifdef HAVE_RUBY_ENCODING_H
 #include <ruby/encoding.h>
 extern rb_encoding *utf8Encoding;
\ No newline at end of file