diff --git a/ChangeLog b/ChangeLog
index bc78575cd6..90290c0766 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jun 10 13:48:38 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* rational.c (nurat_s_convert): need not to initialize optional
+	  argument for rb_scan_args().
+
 Tue Jun 10 12:58:07 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/io/wait/wait.c (FIONREAD_POSSIBLE_P): suppress warnings.
diff --git a/rational.c b/rational.c
index 379551a345..9dfd84f323 100644
--- a/rational.c
+++ b/rational.c
@@ -1422,8 +1422,6 @@ nurat_s_convert(int argc, VALUE *argv, VALUE klass)
 {
     VALUE a1, a2;
 
-    a1 = Qnil;
-    a2 = Qnil;
     rb_scan_args(argc, argv, "02", &a1, &a2);
 
     switch (TYPE(a1)) {