diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index 290bd8a..dc01681 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -110,6 +110,11 @@
 	array[vlan_id % VLAN_GROUP_ARRAY_PART_LEN] = dev;
 }
 
+static inline int is_vlan_dev(struct net_device *dev)
+{
+        return dev->priv_flags & IFF_802_1Q_VLAN;
+}
+
 #define vlan_tx_tag_present(__skb)	((__skb)->vlan_tci & VLAN_TAG_PRESENT)
 #define vlan_tx_tag_get(__skb)		((__skb)->vlan_tci & ~VLAN_TAG_PRESENT)