diff --git a/ChangeLog b/ChangeLog
index 4153c34488..ccaf6a27af 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Feb  9 16:08:55 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* ext/dl/lib/value.rb (DL::ValueUtil.{unsigned_value,signed_value}):
+	  currenly pack/unpack does not accept "q!" and "Q!".
+
 Thu Feb  9 16:01:29 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* ext/fiddle/conversions.c (value_to_generic): src is not guranteed as
diff --git a/ext/dl/lib/dl/value.rb b/ext/dl/lib/dl/value.rb
index 51f96b293b..e99e3cf3bf 100644
--- a/ext/dl/lib/dl/value.rb
+++ b/ext/dl/lib/dl/value.rb
@@ -13,7 +13,7 @@ module DL
       when TYPE_LONG
         [val].pack("l!").unpack("L!")[0]
       when TYPE_LONG_LONG
-        [val].pack("q!").unpack("Q!")[0]
+        [val].pack("q").unpack("Q")[0]
       else
         val
       end
@@ -30,7 +30,7 @@ module DL
       when TYPE_LONG
         [val].pack("L!").unpack("l!")[0]
       when TYPE_LONG_LONG
-        [val].pack("Q!").unpack("q!")[0]
+        [val].pack("Q").unpack("q")[0]
       else
         val
       end