diff --git a/ChangeLog b/ChangeLog
index 5bf1f928c6..54231022a8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Jun 18 22:36:23 2013  Masaya Tarui  <tarui@ruby-lang.org>
+
+	* gc.c (gc_profile_record_flag): reason seems like one-hot encoding.
+
 Tue Jun 18 22:08:53 2013  Zachary Scott  <zachary@zacharyscott.net>
 
 	* ext/objspace/object_tracing.c: Return for ::allocation_generation
diff --git a/gc.c b/gc.c
index 057e6c8862..c85c5520ce 100644
--- a/gc.c
+++ b/gc.c
@@ -161,7 +161,7 @@ typedef enum {
     GPR_FLAG_MALLOC          = 0x08,
     GPR_FLAG_METHOD          = 0x10,
     GPR_FLAG_CAPI            = 0x20,
-    GPR_FLAG_STRESS          = 0x30
+    GPR_FLAG_STRESS          = 0x40
 } gc_profile_record_flag;
 
 typedef struct gc_profile_record {