diff --git a/drivers/net/mmnif.c b/drivers/net/mmnif.c
index 1b70889f..7f2039ca 100644
--- a/drivers/net/mmnif.c
+++ b/drivers/net/mmnif.c
@@ -755,7 +755,7 @@ err_t mmnif_tx(struct netif* netif, struct pbuf* p)
 	else
 		mmnif_write_rx_buffl(dest_ip, pos, p->payload,p->tot_len);
 
-	sleep(1);
+	udelay(300000);
 
 	/* like above ensure we are the only ones editing the hdr */
 	mmnif_lock_rx_hdr(dest_ip);
@@ -1160,7 +1160,7 @@ int mmnif_poll(void* e)
 			 */
 		}
 		mmnif->stats.pll_empty--;
-			sleep(1);
+		udelay(300000);
 		mmnif_rx(mmnif_dev);
 	}