1 files changed, 2 insertions, 2 deletions
diff --git a/constant.h b/constant.h
index 9354241961..3dc9b8d4ef 100644
--- a/constant.h
+++ b/constant.h
@@ -18,8 +18,8 @@ typedef enum {
 
 typedef struct rb_const_entry_struct {
     rb_const_flag_t flag;
-    VALUE value;            /* should be mark */
-    VALUE file;
+    const VALUE value;            /* should be mark */
+    const VALUE file;             /* should be mark */
     int line;
 } rb_const_entry_t;