diff --git a/README b/README
index dbee7ce..aa2f564 100644
--- a/README
+++ b/README
@@ -29,6 +29,11 @@ How to Verify Control Messages
    Listed below are the steps you need to take to enable PGP
    authentication of control messages on your system.
 
+   WARNING: The instructions for INN below are only for very old versions
+   of INN.  If you are using a current version of INN (2.0 or later),
+   please see the documentation that comes with INN rather than following
+   these instructions.
+
    Here is the short and simple version for someone who feels confident
    hacking around the news system and doesn't like to read a lot: