1 files changed, 3 insertions, 4 deletions
diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index e1ec389dc4..7256e6fc16 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -1919,11 +1919,10 @@ End
   end
 
   def test_fcntl_dupfd
-    Tempfile.new(self.class.name) do |f|
-      f.open
-      fd = f.fcntl(Fcntl::F_DUPFD, 500)
+    Tempfile.open(self.class.name) do |f|
+      fd = f.fcntl(Fcntl::F_DUPFD, 255)
       begin
-        assert_equal(fd, 500)
+        assert_equal(fd, 255)
       ensure
         IO.for_fd(fd).close
       end