diff --git a/ChangeLog b/ChangeLog
index b51da37677..40062b5c6a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun May 16 22:17:35 2010  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* eval.c (setup_exception): let SystemStackError#backtrace return an
+	  single element array instead of string itself.  [ruby-core:30196]
+
 Sun May 16 21:51:04 2010  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* parse.y (parser_read_escape, parser_tokadd_escape): allow a hex or
diff --git a/eval.c b/eval.c
index 1948ac9d98..7f58a9765f 100644
--- a/eval.c
+++ b/eval.c
@@ -380,6 +380,7 @@ setup_exception(rb_thread_t *th, int tag, volatile VALUE mesg)
     if (file && !NIL_P(mesg)) {
 	if (mesg == sysstack_error) {
 	    at = rb_enc_sprintf(rb_usascii_encoding(), "%s:%d", file, line);
+	    at = rb_ary_new3(1, at);
 	    rb_iv_set(mesg, "bt", at);
 	}
 	else {