diff --git a/net/tftp.c b/net/tftp.c
index 2d3ee5f..5a5ae22 100644
--- a/net/tftp.c
+++ b/net/tftp.c
@@ -111,7 +111,7 @@
 	 *	We will always be sending some sort of packet, so
 	 *	cobble together the packet headers now.
 	 */
-	pkt = NetTxPacket + ETHER_HDR_SIZE + IP_HDR_SIZE;
+	pkt = NetTxPacket + NetEthHdrSize() + IP_HDR_SIZE;
 
 	switch (TftpState) {