diff --git a/ChangeLog b/ChangeLog
index 829aa472a3..3b05daef63 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Wed Aug 20 18:41:11 2008  Tanaka Akira  <akr@fsij.org>
+
+	* io.c (rb_open_file): don't lookup :mode and :perm in opt.  it is
+	  useless because vmode and perm is overwritten by rb_scan_args
+	  anyway.
+
 Wed Aug 20 18:37:20 2008  Tanaka Akira  <akr@fsij.org>
 
 	* io.c (open_key_args): meaningless MEMCPY removed.
diff --git a/io.c b/io.c
index 3f67d8093c..f2c78397c9 100644
--- a/io.c
+++ b/io.c
@@ -4462,11 +4462,6 @@ rb_open_file(int argc, VALUE *argv, VALUE io)
     if (0 < argc) {
         opt = rb_check_convert_type(argv[argc-1], T_HASH, "Hash", "to_hash");
         if (!NIL_P(opt)) {
-            VALUE v;
-            v = rb_hash_aref(opt, sym_mode);
-            if (!NIL_P(v)) vmode = v;
-            v = rb_hash_aref(opt, sym_perm);
-            if (!NIL_P(v)) perm = v;
             argc -= 1;
         }
     }