diff --git a/drivers/net/dummy.c b/drivers/net/dummy.c
index e31ab3b..58483af 100644
--- a/drivers/net/dummy.c
+++ b/drivers/net/dummy.c
@@ -353,7 +353,7 @@
 	eth_hw_addr_random(dev);
 
 	dev->min_mtu = 0;
-	dev->max_mtu = ETH_MAX_MTU;
+	dev->max_mtu = 0;
 }
 
 static int dummy_validate(struct nlattr *tb[], struct nlattr *data[],
diff --git a/drivers/net/ifb.c b/drivers/net/ifb.c
index 8870bd2..0008da7 100644
--- a/drivers/net/ifb.c
+++ b/drivers/net/ifb.c
@@ -231,6 +231,9 @@
 	eth_hw_addr_random(dev);
 	dev->needs_free_netdev = true;
 	dev->priv_destructor = ifb_dev_free;
+
+	dev->min_mtu = 0;
+	dev->max_mtu = 0;
 }
 
 static netdev_tx_t ifb_xmit(struct sk_buff *skb, struct net_device *dev)