diff --git a/.gdbinit b/.gdbinit
index 4ed4e7f5e3..c86081f6ec 100644
--- a/.gdbinit
+++ b/.gdbinit
@@ -731,8 +731,8 @@ define rb_ps_vm
   if $ps_threads->entries_packed
     set $ps_threads_i = 0
     while $ps_threads_i < $ps_threads->num_entries
-      set $ps_threads_key = (st_data_t)$ps_threads->bins[$ps_threads_i * 2]
-      set $ps_threads_val = (st_data_t)$ps_threads->bins[$ps_threads_i * 2 + 1]
+      set $ps_threads_key = (st_data_t)$ps_threads->as.packed.entries[$ps_threads_i].key
+      set $ps_threads_val = (st_data_t)$ps_threads->as.packed.entries[$ps_threads_i].val
       rb_ps_thread $ps_threads_key $ps_threads_val
       set $ps_threads_i = $ps_threads_i + 1
     end
diff --git a/ChangeLog b/ChangeLog
index ed79598cf5..a525a5c1d0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Apr 23 14:16:45 2012  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* .gdbinit (rb_ps_vm): follow st_table's packing change.
+
 Mon Apr 23 10:43:30 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* configure.in: disable rubygems not to load rbconfig.rb before