diff --git a/.gdbinit b/.gdbinit
index 5bde2604c9..61c18cdf45 100644
--- a/.gdbinit
+++ b/.gdbinit
@@ -268,8 +268,13 @@ define rp
     print (struct RBasic *)($arg0)
   else
   if ($flags & RUBY_T_MASK) == RUBY_T_DATA
-    printf "T_DATA: "
-    print (struct RData *)($arg0)
+    if ((struct RTypedData *)($arg0))->typed_flag == 1
+      printf "T_DATA(typed): "
+      print (struct RTypedData *)($arg0)
+    else
+      printf "T_DATA: "
+      print (struct RData *)($arg0)
+    end
   else
   if ($flags & RUBY_T_MASK) == RUBY_T_MATCH
     printf "T_MATCH: "
diff --git a/ChangeLog b/ChangeLog
index 35fc0238b0..6ab04ca445 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Sat Jun  5 10:03:31 2010  Tanaka Akira  <akr@fsij.org>
+
+	* .gdbinit (rp): detect and show RTypedData.
+
 Sat Jun  5 09:56:57 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ruby.c (process_options): revert r25330, so that $0 can be seen