diff --git a/ChangeLog b/ChangeLog
index 91559a4e61..a140b25d15 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Oct 11 02:50:34 2012  Koichi Sasada  <ko1@atdot.net>
+
+	* iseq.c (insn_operand_intern): add support disasm TS_CALLINFO
+	  operands.
+
 Wed Oct 10 15:12:48 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* test/ruby/test_process.rb (TestProcess#test_execopts_gid): skip on
diff --git a/iseq.c b/iseq.c
index 58f5905f33..42cce0bb0b 100644
--- a/iseq.c
+++ b/iseq.c
@@ -1040,6 +1040,10 @@ insn_operand_intern(rb_iseq_t *iseq,
 	ret = rb_sprintf("<ic:%"PRIdPTRDIFF">", (struct iseq_inline_cache_entry *)op - iseq->ic_entries);
 	break;
 
+      case TS_CALLINFO:
+	ret = rb_sprintf("<ci:%"PRIdPTRDIFF">", (struct iseq_inline_cache_entry *)op - iseq->callinfo_entries);
+	break;
+
       case TS_CDHASH:
 	ret = rb_str_new2("<cdhash>");
 	break;