diff --git a/root/certbot-prepare.sh b/root/certbot-prepare.sh
index 6c4d93f..7931fc0 100644
--- a/root/certbot-prepare.sh
+++ b/root/certbot-prepare.sh
@@ -47,7 +47,7 @@ function better_exit {
 }
 
 # Check APPRISE_URL is set if either NOTIFY_ON_SUCCESS or NOTIFY_ON_FAILURE are set
-if [ ! -z "${NOTIFY_ON_SUCCESS}" ] || [ ! -z "${NOTIFY_ON_FAILURE}" ] && [ -z "${APPRISE_URL}" ]; then
+if [ "${NOTIFY_ON_SUCCESS}" = "true" ] || [ "${NOTIFY_ON_FAILURE}" = "true" ] && [ -z "${APPRISE_URL}" ]; then
 
     echo "You have notifications enabled but have not set APPRISE_URL. Please set APPRISE_URL and restart the container."
     better_exit