diff --git a/ChangeLog b/ChangeLog
index 981afba581..220c1193d6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Oct 12 19:07:55 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* error.c (syserr_initialize): taint message if mesg is given
+	  and it is tainted.
+
 Tue Oct 12 18:25:43 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* io.c (rb_io_ungetc): always see Bignum. On 32bit valid value
diff --git a/error.c b/error.c
index 94126f709b..4ad252bde1 100644
--- a/error.c
+++ b/error.c
@@ -1059,6 +1059,7 @@ syserr_initialize(int argc, VALUE *argv, VALUE self)
 	    if (le != me && rb_enc_asciicompat(me))
 		le = me;
 	}/* else assume err is non ASCII string. */
+	if (OBJ_TAINTED(str)) OBJ_TAINT(mesg);
 	rb_enc_associate(mesg, le);
     }
     else {