1 files changed, 1 insertions, 1 deletions
diff --git a/internal.h b/internal.h
index b931c115df..f8baba48c1 100644
--- a/internal.h
+++ b/internal.h
@@ -873,7 +873,7 @@ struct RHash {
         struct ar_table_struct *ar; /* possibly 0 */
     } as;
     int iter_lev;
-    VALUE ifnone;
+    const VALUE ifnone;
 };
 
 #ifdef RHASH_ITER_LEV