diff --git a/platform/mb851/contiki-conf.h b/platform/mb851/contiki-conf.h
index 9fe19aa5a..7bad02f33 100644
--- a/platform/mb851/contiki-conf.h
+++ b/platform/mb851/contiki-conf.h
@@ -110,7 +110,7 @@ typedef unsigned short uip_stats_t;
 #define UIP_CONF_ND6_MAX_NEIGHBORS		2
 #define UIP_CONF_ND6_MAX_DEFROUTERS		1
 #define UIP_CONF_IP_FORWARD			0
-#define UIP_CONF_BUFFER_SIZE			200
+#define UIP_CONF_BUFFER_SIZE			140
 #define UIP_CONF_MAX_CONNECTIONS		6
 #define UIP_CONF_MAX_LISTENPORTS		6
 #define UIP_CONF_UDP_CONNS			3