diff --git a/Lib/mailbox.py b/Lib/mailbox.py
index 17e062e..6580099 100755
--- a/Lib/mailbox.py
+++ b/Lib/mailbox.py
@@ -1993,7 +1993,7 @@
     # that the two characters preceding "From " are \n\n or the beginning of
     # the file.  Fixing this would require a more extensive rewrite than is
     # necessary.  For convenience, we've added a PortableUnixMailbox class
-    # which uses the more lenient _fromlinepattern regular expression.
+    # which does no checking of the format of the 'From' line.
 
     _fromlinepattern = (r"From \s*[^\s]+\s+\w\w\w\s+\w\w\w\s+\d?\d\s+"
                         r"\d?\d:\d\d(:\d\d)?(\s+[^\s]+)?\s+\d\d\d\d\s*"