diff --git a/ChangeLog b/ChangeLog
index ff8fa5f0f3..118796df9b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jul 28 23:23:08 2003  Nobuyoshi Nakada  <nobu.nokada@softhome.net>
+
+	* file.c (Init_File): IO should include File::Const.
+	  [ruby-dev:20964]
+
 Mon Jul 28 18:53:03 2003  WATANABE Hirofumi  <eban@ruby-lang.org>
 
 	* ext/openssl/extconf.rb: check again after pkg-config for MinGW on
diff --git a/file.c b/file.c
index 49d931be40..1449303f06 100644
--- a/file.c
+++ b/file.c
@@ -2578,7 +2578,6 @@ rb_file_const(name, value)
     VALUE value;
 {
     rb_define_const(rb_mFConst, name, value);
-    rb_define_const(rb_cIO, name, value);
 }
 
 static int
@@ -2919,6 +2918,7 @@ Init_File()
     rb_define_method(rb_cFile, "flock", rb_file_flock, 1);
 
     rb_mFConst = rb_define_module_under(rb_cFile, "Constants");
+    rb_include_module(rb_cIO, rb_mFConst);
     rb_file_const("LOCK_SH", INT2FIX(LOCK_SH));
     rb_file_const("LOCK_EX", INT2FIX(LOCK_EX));
     rb_file_const("LOCK_UN", INT2FIX(LOCK_UN));