diff --git a/ChangeLog b/ChangeLog
index 91eb86565f..1a03df7fce 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Apr 15 19:20:14 2008  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* io.c: #undef rb_argv moved before #define.
+
 Tue Apr 15 18:02:17 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* include/ruby/intern.h (rb_argv): replaced with rb_get_argv().
diff --git a/io.c b/io.c
index 59fd378618..9524894ea3 100644
--- a/io.c
+++ b/io.c
@@ -5037,6 +5037,7 @@ argf_alloc(VALUE klass)
     return argf;
 }
 
+#undef rb_argv
 #define filename          ARGF.filename
 #define current_file      ARGF.current_file
 #define gets_lineno       ARGF.gets_lineno
@@ -7244,8 +7245,6 @@ rb_get_argv(void)
     return rb_argv;
 }
 
-#undef rb_argv
-
 /*
  *  Class <code>IO</code> is the basis for all input and output in Ruby.
  *  An I/O stream may be <em>duplexed</em> (that is, bidirectional), and