diff --git a/proftpd/README.md b/proftpd/README.md
index dae8abef..6e96e05a 100644
--- a/proftpd/README.md
+++ b/proftpd/README.md
@@ -41,5 +41,5 @@ proftpd_accounts:
 For generate the sha512 version of yours password :
 
 ~~~
-echo "test" | mkpasswd --method=sha-512 -
+printf "test" | mkpasswd --stdin --method=sha-512
 ~~~