diff --git a/gluon/gluon-core/generate/lib/gluon/upgrade/core/invariant/011-ntp-servers b/gluon/gluon-core/generate/lib/gluon/upgrade/core/invariant/011-ntp-servers
new file mode 100755
index 0000000..fa69b05
--- /dev/null
+++ b/gluon/gluon-core/generate/lib/gluon/upgrade/core/invariant/011-ntp-servers
@@ -0,0 +1,12 @@
+#!/bin/sh
+
+[ -n '@ntp_servers@' ] || exit 0
+
+
+uci delete system.ntp.server
+
+for server in @ntp_servers@; do
+	uci add_list system.ntp.server="$server"
+done
+
+uci commit system