diff --git a/README b/README
index b8d7d00..f829eac 100644
--- a/README
+++ b/README
@@ -81,7 +81,7 @@ Available parameters are:
   -mN    : display message number N
   -dN    : delete message number N
   -fsender : delete message from sender
-  -f're'   : delete message from senders matching regular expression re
+  -F're'   : delete message from senders matching regular expression re
   -Stext : delete all messages that have/contain text as Subject
   -h're'   : delete all messages with headers matching regular expression re (case insensitive)
   -e're'   : delete all messages with headers NOT matching regular expression re (case insensitive)