diff --git a/files/new_mail_alias b/files/new_mail_alias
index a445344..d37c0ef 100644
--- a/files/new_mail_alias
+++ b/files/new_mail_alias
@@ -1,4 +1,5 @@
 #!/bin/bash
+set -euo pipefail
 # shellcheck disable=SC1091
 [ -r /var/lib/from_repos/ad_scripts/shared_functions.sh ] && . /var/lib/from_repos/ad_scripts/shared_functions.sh
 function usage() {