diff --git a/drivers/net/ethernet/dec/tulip/de2104x.c b/drivers/net/ethernet/dec/tulip/de2104x.c
index d305d1b24b0a4816b36063f0e7690036925a075d..42b798a3fad484f01fff3c0eff6cfbf419479b34 100644
--- a/drivers/net/ethernet/dec/tulip/de2104x.c
+++ b/drivers/net/ethernet/dec/tulip/de2104x.c
@@ -417,7 +417,10 @@ static void de_rx (struct de_private *de)
 		if (status & DescOwn)
 			break;
 
-		len = ((status >> 16) & 0x7ff) - 4;
+		/* the length is actually a 15 bit value here according
+		 * to Table 4-1 in the DE2104x spec so mask is 0x7fff
+		 */
+		len = ((status >> 16) & 0x7fff) - 4;
 		mapping = de->rx_skb[rx_tail].mapping;
 
 		if (unlikely(drop)) {