diff --git a/lib/tempfile.rb b/lib/tempfile.rb
index eeed2534a9..cd512bb1c5 100644
--- a/lib/tempfile.rb
+++ b/lib/tempfile.rb
@@ -550,8 +550,8 @@ end
 #
 # Implementation note:
 #
-# The keyword argument <tt>anonymous=true</tt> is implemented using FILE_SHARE_DELETE on Windows.
-# O_TMPFILE is used on Linux.
+# The keyword argument <tt>anonymous=true</tt> is implemented using +FILE_SHARE_DELETE+ on Windows.
+# +O_TMPFILE+ is used on Linux.
 #
 # Related: Tempfile.new.
 #