diff --git a/internal/variable.h b/internal/variable.h
index 4b67bef907..1a19e8964b 100644
--- a/internal/variable.h
+++ b/internal/variable.h
@@ -16,7 +16,7 @@
 
 /* global variable */
 
-#define ROBJECT_TRANSIENT_FLAG    FL_USER13
+#define ROBJECT_TRANSIENT_FLAG    FL_USER2
 
 /* variable.c */
 void rb_gc_mark_global_tbl(void);