diff --git a/nixos/modules/programs/ssmtp.nix b/nixos/modules/programs/ssmtp.nix
index 8039763faccc..8b500f0383f4 100644
--- a/nixos/modules/programs/ssmtp.nix
+++ b/nixos/modules/programs/ssmtp.nix
@@ -124,7 +124,8 @@ in
         example = "/run/keys/ssmtp-authpass";
         description = ''
           Path to a file that contains the password used for SMTP auth. The file
-          should not contain a trailing newline, if the password does not contain one.
+          should not contain a trailing newline, if the password does not contain one
+          (e.g. use <command>echo -n "password" > file</command>).
           This file should be readable by the users that need to execute ssmtp.
         '';
       };