1 files changed, 1 insertions, 1 deletions
diff --git a/ruby.h b/ruby.h
index e0025083e5..6a2d2db4c0 100644
--- a/ruby.h
+++ b/ruby.h
@@ -378,7 +378,7 @@ struct RString {
     } as;
 };
 #define RSTRING_NOEMBED FL_USER1
-#define RSTRING_EMBED_LEN_MASK (FL_USER2|FL_USER3|FL_USER4|FL_USER5)
+#define RSTRING_EMBED_LEN_MASK (FL_USER2|FL_USER3|FL_USER4|FL_USER5|FL_USER6)
 #define RSTRING_EMBED_LEN_SHIFT (FL_USHIFT+2)
 #define RSTRING_LEN(str) \
     (!(RBASIC(str)->flags & RSTRING_NOEMBED) ? \