diff --git a/ChangeLog b/ChangeLog
index 23e4c8d00b..9ec8b2b53d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Sep 17 01:56:27 2008  Tanaka Akira  <akr@fsij.org>
+
+	* test/ruby/test_io_m17n.rb: use __FILE__ instead of /dev/null.
+	  [ruby-dev:36327]
+
 Wed Sep 17 01:33:11 2008  Tanaka Akira  <akr@fsij.org>
 
 	* include/ruby/oniguruma.h (OnigEncodingTypeST): add precise_ret
diff --git a/test/ruby/test_io_m17n.rb b/test/ruby/test_io_m17n.rb
index 237698b868..3c2e5112d8 100644
--- a/test/ruby/test_io_m17n.rb
+++ b/test/ruby/test_io_m17n.rb
@@ -809,28 +809,28 @@ EOT
 
   def test_set_encoding_binmode
     assert_raise(ArgumentError) {
-      open("/dev/null", "rt") {|f|
+      open(__FILE__, "rt") {|f|
         f.set_encoding("iso-2022-jp")
       }
     }
     assert_raise(ArgumentError) {
-      open("/dev/null", "r") {|f|
+      open(__FILE__, "r") {|f|
         f.set_encoding("iso-2022-jp")
       }
     }
     assert_nothing_raised {
-      open("/dev/null", "rb") {|f|
+      open(__FILE__, "rb") {|f|
         f.set_encoding("iso-2022-jp")
       }
     }
     assert_nothing_raised {
-      open("/dev/null", "r") {|f|
+      open(__FILE__, "r") {|f|
         f.binmode
         f.set_encoding("iso-2022-jp")
       }
     }
     assert_nothing_raised {
-      open("/dev/null", "rt") {|f|
+      open(__FILE__, "rt") {|f|
         f.binmode
         f.set_encoding("iso-2022-jp")
       }