diff --git a/package/gluon-mesh-vpn-openvpn/check_site.lua b/package/gluon-mesh-vpn-openvpn/check_site.lua
index 392f6f54..c75d473e 100644
--- a/package/gluon-mesh-vpn-openvpn/check_site.lua
+++ b/package/gluon-mesh-vpn-openvpn/check_site.lua
@@ -1 +1,2 @@
+need_number({'mesh_vpn', 'openvpn', 'mtu'})
 need_table({'mesh_vpn', 'openvpn', 'config'})