diff --git a/rsa-converter b/rsa-converter
index 0dac3da..bbd3c07 100755
--- a/rsa-converter
+++ b/rsa-converter
@@ -27,7 +27,7 @@ sub usage() {
 This program converts RSA keys between various formats.
 You must specify at least one output format.
 
-usage: $0 [-hrcpqs] < file
+usage: $0 [-hrdpqs] < file
  -h : print this message
  -r : output public key in Base64 RFC 3110 format
  -d : output public key in hexadecimal DER format