diff --git a/etc/chrony/conf.d/require-nts.conf b/etc/chrony/conf.d/require-nts.conf
new file mode 100644
index 00000000..91f217d8
--- /dev/null
+++ b/etc/chrony/conf.d/require-nts.conf
@@ -0,0 +1,5 @@
+# authselectmode "require" means that only NTS peers get used. Refer to
+# "man chrony.conf" for other options
+# NOTE: This will just mark the configued NTP sources as ineligible for
+# synchronisation from, they will regardless be observed.
+authselectmode require