diff --git a/src/yang/etsi-nfv-common.yang b/src/yang/etsi-nfv-common.yang
index 841e03ba940eca8e8acd99a4723b81c9c3b4a4bd..dc28e78c3c44ff20d96c196f2a1ae12d90883442 100644
--- a/src/yang/etsi-nfv-common.yang
+++ b/src/yang/etsi-nfv-common.yang
@@ -437,6 +437,7 @@ submodule etsi-nfv-common {
         type identityref {
           base layer-protocol;
         }
+	min-elements 1;
         description
           "Identifies the protocols that the VL uses (Ethernet,
            MPLS, ODU2, IPV4, IPV6, Pseudo-Wire). The top layer