1 files changed, 2 insertions, 1 deletions
diff --git a/ruby.h b/ruby.h
index 0accbbdb6b..97c751086a 100644
--- a/ruby.h
+++ b/ruby.h
@@ -275,10 +275,11 @@ struct RBignum {
     USHORT *digits;
 };
 
-#define R_CAST(st) (struct st*)
+#define R_CAST(st)   (struct st*)
 #define RBASIC(obj)  (R_CAST(RBasic)(obj))
 #define ROBJECT(obj) (R_CAST(RObject)(obj))
 #define RCLASS(obj)  (R_CAST(RClass)(obj))
+#define RMODULE(obj) RCLASS(obj)
 #define RFLOAT(obj)  (R_CAST(RFloat)(obj))
 #define RSTRING(obj) (R_CAST(RString)(obj))
 #define RREGEXP(obj) (R_CAST(RRegexp)(obj))