diff --git a/ChangeLog b/ChangeLog
index 1affab510e..85c9b47c50 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Nov 11 01:52:52 2004  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* error.c (syserr_initialize): use stringified object.
+	  [ruby-dev:24768]
+
 Wed Nov 10 22:49:01 2004  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* lib/delegate.rb (SimpleDelegator::dup): wrong number of
diff --git a/error.c b/error.c
index 50e50d01a6..ebc431107b 100644
--- a/error.c
+++ b/error.c
@@ -956,7 +956,7 @@ syserr_initialize(argc, argv, self)
     if (!NIL_P(mesg)) {
 	VALUE str = mesg;
 	StringValue(str);
-	mesg = rb_str_new(0, strlen(err)+RSTRING(mesg)->len+3);
+	mesg = rb_str_new(0, strlen(err)+RSTRING(str)->len+3);
 	sprintf(RSTRING(mesg)->ptr, "%s - %.*s", err,
 		(int)RSTRING(str)->len, RSTRING(str)->ptr);
 	rb_str_resize(mesg, strlen(RSTRING(mesg)->ptr));