1 files changed, 1 insertions, 1 deletions
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));