diff --git a/resources/com/cadoles/common/add-letsencrypt-ca.sh b/resources/com/cadoles/common/add-letsencrypt-ca.sh
index 7cd80f4..1e8d2fe 100644
--- a/resources/com/cadoles/common/add-letsencrypt-ca.sh
+++ b/resources/com/cadoles/common/add-letsencrypt-ca.sh
@@ -3,7 +3,15 @@
 set -eo pipefail
 
 DESTDIR=/usr/local/share/ca-certificates
+if [ ! -d "$DESTDIR" ]; then
+	DESTDIR=/etc/pki/ca-trust/source/anchors
+fi
+
 UPDATE_CERTS_CMD=update-ca-certificates
+if [ -z "$(which $UPDATE_CERTS_CMD)" ]; then
+	UPDATE_CERTS_CMD="update-ca-trust extract"
+fi
+
 CERTS="$(cat <<EOF
 https://letsencrypt.org/certs/isrgrootx1.pem
 https://letsencrypt.org/certs/isrg-root-x2.pem