diff --git a/include/mruby/range.h b/include/mruby/range.h
index ee6eb8d1d..500a941d5 100644
--- a/include/mruby/range.h
+++ b/include/mruby/range.h
@@ -14,7 +14,7 @@
  */
 MRB_BEGIN_DECL
 
-#if defined(MRB_NAN_BOXING) || defined(MRB_WORD_BOXING)
+#if defined(MRB_NAN_BOXING) && defined(MRB_64BIT) || defined(MRB_WORD_BOXING)
 # define MRB_RANGE_EMBED
 #endif