diff --git a/ChangeLog b/ChangeLog
index 2a8e4a9259..2a92695a6e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Sat Oct 25 01:29:34 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* ext/mathn/rational/rational.c: undef duplicated macro definition
+	  first to shut up the warning.
+
+	* ext/mathn/rational/rational.c (rb_rational_new_mathn): specify
+	  omitted return value.
+
 Sat Oct 25 00:14:41 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* array.c (rb_ary_sample): fixed sizes and randomness.
diff --git a/ext/mathn/rational/rational.c b/ext/mathn/rational/rational.c
index 74b7e4999f..7a169f4329 100644
--- a/ext/mathn/rational/rational.c
+++ b/ext/mathn/rational/rational.c
@@ -1191,10 +1191,12 @@ rb_rational_raw(VALUE x, VALUE y)
 
 #ifdef EXT_MATHN
 
+#undef rb_rational_new1
+#undef rb_rational_new2
 #define rb_rational_new1(x) rb_rational_new_mathn(x, INT2FIX(1))
 #define rb_rational_new2(x,y) rb_rational_new_mathn(x, y)
 
-static
+static VALUE
 rb_rational_new_mathn(VALUE x, VALUE y)
 {
     return nurat_s_canonicalize_internal(rb_cRational, x, y);