diff --git a/src/include/ipv4/lwip/inet.h b/src/include/ipv4/lwip/inet.h
index ec6d0909..b19cad96 100644
--- a/src/include/ipv4/lwip/inet.h
+++ b/src/include/ipv4/lwip/inet.h
@@ -94,6 +94,15 @@ struct in_addr {
 
 #define IN_LOOPBACKNET      IP_LOOPBACKNET
 
+#ifndef INET_ADDRSTRLEN
+#define INET_ADDRSTRLEN     IP4ADDR_STRLEN_MAX
+#endif
+#if LWIP_IPV6
+#ifndef INET6_ADDRSTRLEN
+#define INET6_ADDRSTRLEN    IP6ADDR_STRLEN_MAX
+#endif
+#endif
+
 #define inet_addr_from_ipaddr(target_inaddr, source_ipaddr) ((target_inaddr)->s_addr = ip4_addr_get_u32(source_ipaddr))
 #define inet_addr_to_ipaddr(target_ipaddr, source_inaddr)   (ip4_addr_set_u32(target_ipaddr, (source_inaddr)->s_addr))
 /* ATTENTION: the next define only works because both s_addr and ip_addr_t are an u32_t effectively! */
diff --git a/src/include/ipv4/lwip/ip4_addr.h b/src/include/ipv4/lwip/ip4_addr.h
index 923d4b06..8de6363f 100644
--- a/src/include/ipv4/lwip/ip4_addr.h
+++ b/src/include/ipv4/lwip/ip4_addr.h
@@ -228,6 +228,9 @@ u8_t ip4_addr_netmask_valid(u32_t netmask);
 #define ip4_addr3_16(ipaddr) ((u16_t)ip4_addr3(ipaddr))
 #define ip4_addr4_16(ipaddr) ((u16_t)ip4_addr4(ipaddr))
 
+#define IP4ADDR_STRLEN_MAX  16
+#define IPADDR_STRLEN_MAX   IP4ADDR_STRLEN_MAX
+
 /** For backwards compatibility */
 #define ip_ntoa(ipaddr)  ipaddr_ntoa(ipaddr)
 
diff --git a/src/include/ipv6/lwip/ip6_addr.h b/src/include/ipv6/lwip/ip6_addr.h
index 1990e93e..21f6c535 100644
--- a/src/include/ipv6/lwip/ip6_addr.h
+++ b/src/include/ipv6/lwip/ip6_addr.h
@@ -85,8 +85,6 @@ extern const ip6_addr_t ip6_addr_any;
 #define IP6_ADDR_ANY         ((ip6_addr_t *)&ip6_addr_any)
 
 
-
-
 #if BYTE_ORDER == BIG_ENDIAN
 /** Set an IPv6 partial address given by byte-parts. */
 #define IP6_ADDR(ip6addr, index, a,b,c,d) \
@@ -146,7 +144,6 @@ Little-endian version, stored in network order (no htonl). */
                                         (dest)->addr[3] = (src) == NULL ? 0 : htonl((src)->addr[3]);}while(0)
 
 
-
 /**
  * Determine if two IPv6 address are on the same network.
  *
@@ -264,7 +261,7 @@ Little-endian version, stored in network order (no htonl). */
 #define ip6_addr_isdeprecated(addr_state) (addr_state == IP6_ADDR_DEPRECATED)
 
 #define ip6_addr_debug_print(debug, ipaddr) \
-  LWIP_DEBUGF(debug, ("%" X16_F ":%" X16_F ":%" X16_F ":%" X16_F ":%" X16_F ":%" X16_F ":%" X16_F ":%" X16_F, \
+  LWIP_DEBUGF(debug, ("%" X16_F ":%" X16_F ":%" X16_F ":%" X16_F ":%" X16_F ":%" X16_F ":%" X16_F ":%" X16_F, \
                       ipaddr != NULL ? IP6_ADDR_BLOCK1(ipaddr) : 0,    \
                       ipaddr != NULL ? IP6_ADDR_BLOCK2(ipaddr) : 0,    \
                       ipaddr != NULL ? IP6_ADDR_BLOCK3(ipaddr) : 0,    \
@@ -274,6 +271,8 @@ Little-endian version, stored in network order (no htonl). */
                       ipaddr != NULL ? IP6_ADDR_BLOCK7(ipaddr) : 0,    \
                       ipaddr != NULL ? IP6_ADDR_BLOCK8(ipaddr) : 0))
 
+#define IP6ADDR_STRLEN_MAX    46
+
 int ip6addr_aton(const char *cp, ip6_addr_t *addr);
 /** returns ptr to static buffer; not reentrant! */
 char *ip6addr_ntoa(const ip6_addr_t *addr);