diff --git a/tiny-ec2-bootstrap b/tiny-ec2-bootstrap
index e5ae497..3108283 100644
--- a/tiny-ec2-bootstrap
+++ b/tiny-ec2-bootstrap
@@ -86,7 +86,7 @@ _resize_root_partition() {
 }
 
 _disable_password() {
-	echo "$1:*" | chpasswd -e
+	passwd -l "$1"
 }
 
 start() {