--- a/drivers/net/ethernet/lantiq_etop.c
+++ b/drivers/net/ethernet/lantiq_etop.c
@@ -31,6 +31,7 @@
 #include <linux/mm.h>
 #include <linux/platform_device.h>
 #include <linux/ethtool.h>
+#include <linux/if_vlan.h>
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/io.h>
@@ -764,8 +765,10 @@ ltq_etop_change_mtu(struct net_device *d
 		struct ltq_etop_priv *priv = netdev_priv(dev);
 		unsigned long flags;
 
+		int max = ETH_HLEN + VLAN_HLEN + new_mtu + ETH_FCS_LEN;
+
 		spin_lock_irqsave(&priv->lock, flags);
-		ltq_etop_w32((ETOP_PLEN_UNDER << 16) | new_mtu,
+		ltq_etop_w32((ETOP_PLEN_UNDER << 16) | max,
 			LTQ_ETOP_IGPLEN);
 		spin_unlock_irqrestore(&priv->lock, flags);
 	}
