diff --git a/drivers/net/sungem.c b/drivers/net/sungem.c
index 253e96e..334c6cf 100644
--- a/drivers/net/sungem.c
+++ b/drivers/net/sungem.c
@@ -1030,7 +1030,7 @@
 		u64 csum_start_off, csum_stuff_off;
 
 		csum_start_off = (u64) (skb->h.raw - skb->data);
-		csum_stuff_off = (u64) ((skb->h.raw + skb->csum) - skb->data);
+		csum_stuff_off = csum_start_off + skb->csum_offset;
 
 		ctrl = (TXDCTRL_CENAB |
 			(csum_start_off << 15) |