diff --git a/ChangeLog b/ChangeLog
index 2ed7a864e5..91306648ce 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun May 25 23:48:21 2003  Nobuyoshi Nakada  <nobu.nokada@softhome.net>
+
+	* bignum.c (rb_quad_pack): should negate negative bignum.
+	  (ruby-bugs-ja:PR#474)
+
 Sun May 25 03:27:25 2003  Minero Aoki  <aamine@loveruby.net>
 
 	* lib/net/smtp.rb: support LOGIN authentication, based on
diff --git a/bignum.c b/bignum.c
index 01c882476e..5992662d42 100644
--- a/bignum.c
+++ b/bignum.c
@@ -206,6 +206,7 @@ rb_quad_pack(buf, val)
 	    q = BIGUP(q);
 	    q += ds[len];
 	}
+	if (!RBIGNUM(val)->sign) q = -q;
     }
     memcpy(buf, (char*)&q, SIZEOF_LONG_LONG);
 }