diff --git a/drivers/net/pppoe.c b/drivers/net/pppoe.c
index 5666ed9..0adee73 100644
--- a/drivers/net/pppoe.c
+++ b/drivers/net/pppoe.c
@@ -600,6 +600,7 @@
 		po->chan.hdrlen = (sizeof(struct pppoe_hdr) +
 				   dev->hard_header_len);
 
+		po->chan.mtu = dev->mtu - sizeof(struct pppoe_hdr);
 		po->chan.private = sk;
 		po->chan.ops = &pppoe_chan_ops;