diff --git a/scripts/ping-charles.sh b/scripts/ping-charles.sh
index b21d02a..5d9f142 100755
--- a/scripts/ping-charles.sh
+++ b/scripts/ping-charles.sh
@@ -28,7 +28,7 @@ set -a; . "$CONF"; set +a
 send_one() {
   printf 'From: %s\nTo: %s\nSubject: MOPAC %s\nContent-Type: text/plain; charset=UTF-8\n\n%s\n' \
     "$PING_FROM" "$DEST" "$SEV" "$1" \
-  | curl -sS --max-time 30 --url "smtp://$PING_SMTP_HOST" \
+  | curl -sS --max-time 30 --ssl-reqd --url "smtp://$PING_SMTP_HOST" \
       --mail-from "$PING_FROM" --mail-rcpt "$DEST" \
       -u "$PING_SMTP_USER:$PING_SMTP_PASS" \
       -T - && return 0 || return 1