diff --git a/ChangeLog b/ChangeLog
index ed524c4b52..a97ebc9658 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jul  9 09:34:14 2015  Koichi Sasada  <ko1@atdot.net>
+
+	* vm_core.h (rb_control_frame_t): fix comments (layout index).
+
 Thu Jul  9 09:25:50 2015  Zachary Scott  <e@zzak.io>
 
         * parse.y: Improve duplicate key warning with patch by @andremedeiros
diff --git a/vm_core.h b/vm_core.h
index 5d210c6ae3..6e1e41d464 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -527,12 +527,12 @@ typedef struct rb_control_frame_struct {
     rb_iseq_t *iseq;		/* cfp[2] */
     VALUE flag;			/* cfp[3] */
     VALUE self;			/* cfp[4] / block[0] */
-    VALUE *ep;			/* cfp[6] / block[1] */
-    rb_iseq_t *block_iseq;	/* cfp[7] / block[2] */
-    VALUE proc;			/* cfp[8] / block[3] */
+    VALUE *ep;			/* cfp[5] / block[1] */
+    rb_iseq_t *block_iseq;	/* cfp[6] / block[2] */
+    VALUE proc;			/* cfp[7] / block[3] */
 
 #if VM_DEBUG_BP_CHECK
-    VALUE *bp_check;		/* cfp[9] */
+    VALUE *bp_check;		/* cfp[8] */
 #endif
 } rb_control_frame_t;