diff --git a/arch/arm/src/lpc17xx/lpc17_emacram.h b/arch/arm/src/lpc17xx/lpc17_emacram.h
index 98eaa91b97..3561b72ba8 100755
--- a/arch/arm/src/lpc17xx/lpc17_emacram.h
+++ b/arch/arm/src/lpc17xx/lpc17_emacram.h
@@ -209,7 +209,7 @@
 #define LPC17_PKTMEM_SIZE     (LPC17_EMACRAM_SIZE-LPC17_DESCTAB_SIZE)
 #define LPC17_PKTMEM_END      (LPC17_EMACRAM_BASE+LPC17_PKTMEM_SIZE)
 
-#define LPC17_MAXPACKET_SIZE  ((CONFIG_NET_BUFSIZE + 3 + 2) & ~3)
+#define LPC17_MAXPACKET_SIZE  ((CONFIG_NET_BUFSIZE + CONFIG_NET_GUARDSIZE + 3) & ~3)
 #define LPC17_NTXPKTS         CONFIG_NET_NTXDESC
 #define LPC17_NRXPKTS         CONFIG_NET_NRXDESC
 
diff --git a/arch/arm/src/lpc17xx/lpc17_ethernet.c b/arch/arm/src/lpc17xx/lpc17_ethernet.c
index 3efa3df03b..de015bcb94 100644
--- a/arch/arm/src/lpc17xx/lpc17_ethernet.c
+++ b/arch/arm/src/lpc17xx/lpc17_ethernet.c
@@ -53,6 +53,7 @@
 #include <nuttx/mii.h>
 
 #include <net/uip/uip.h>
+#include <net/uip/uipopt.h>
 #include <net/uip/uip-arp.h>
 #include <net/uip/uip-arch.h>
 
@@ -809,7 +810,7 @@ static void lpc17_rxdone(struct lpc17_driver_s *priv)
        * imply that the packet is too big.
        */
  
-      /* else */ if (pktlen > CONFIG_NET_BUFSIZE+2)
+      /* else */ if (pktlen > CONFIG_NET_BUFSIZE + CONFIG_NET_GUARDSIZE)
         {
           nlldbg("Too big. considx: %08x prodidx: %08x pktlen: %d rxstat: %08x\n",
                  considx, prodidx, pktlen, *rxstat);