diff --git a/setup-cron.sh b/setup-cron.sh
index dfa2f53..b02c779 100644
--- a/setup-cron.sh
+++ b/setup-cron.sh
@@ -5,6 +5,7 @@ set -o pipefail
 
 cron_schedule="${CRON_SCHEDULE:?CRON_SCHEDULE not set}"
 
-echo "$cron_schedule /usr/bin/backup.sh" > /etc/crontabs/root
+echo "$cron_schedule /usr/bin/backup.sh" | crontab -
+crontab -l
 
 crond -f -d8 -L /dev/stdout