diff --git a/features/FEATURE_LWIP/lwip-interface/lwipopts.h b/features/FEATURE_LWIP/lwip-interface/lwipopts.h
index 608cc994e7..c2ae175c06 100644
--- a/features/FEATURE_LWIP/lwip-interface/lwipopts.h
+++ b/features/FEATURE_LWIP/lwip-interface/lwipopts.h
@@ -150,6 +150,12 @@
 #ifdef MBED_CONF_LWIP_PBUF_POOL_BUFSIZE
 #undef PBUF_POOL_BUFSIZE
 #define PBUF_POOL_BUFSIZE           MBED_CONF_LWIP_PBUF_POOL_BUFSIZE
+#else
+#if LWIP_IPV6
+#define PBUF_POOL_BUFSIZE               LWIP_MEM_ALIGN_SIZE(TCP_MSS+20+40+PBUF_LINK_ENCAPSULATION_HLEN+PBUF_LINK_HLEN)
+#else
+#define PBUF_POOL_BUFSIZE               LWIP_MEM_ALIGN_SIZE(TCP_MSS+20+20+PBUF_LINK_ENCAPSULATION_HLEN+PBUF_LINK_HLEN)
+#endif
 #endif
 
 #ifdef MBED_CONF_LWIP_MEM_SIZE