diff --git a/src/api/netdb.c b/src/api/netdb.c
index 4d85dba6..fd0a1497 100644
--- a/src/api/netdb.c
+++ b/src/api/netdb.c
@@ -346,7 +346,7 @@ lwip_getaddrinfo(const char *nodename, const char *servname,
     }
   }
 
-  total_size = sizeof(struct addrinfo) + sizeof(struct sockaddr_in);
+  total_size = sizeof(struct addrinfo) + sizeof(struct sockaddr_storage);
   if (nodename != NULL) {
     namelen = strlen(nodename);
     if (namelen > DNS_MAX_NAME_LENGTH) {
@@ -395,11 +395,11 @@ lwip_getaddrinfo(const char *nodename, const char *servname,
   }
   if (nodename != NULL) {
     /* copy nodename to canonname if specified */
-    ai->ai_canonname = ((char*)ai + sizeof(struct addrinfo) + sizeof(struct sockaddr_in));
+    ai->ai_canonname = ((char*)ai + sizeof(struct addrinfo) + sizeof(struct sockaddr_storage));
     MEMCPY(ai->ai_canonname, nodename, namelen);
     ai->ai_canonname[namelen] = 0;
   }
-  ai->ai_addrlen = sizeof(struct sockaddr_in);
+  ai->ai_addrlen = sizeof(struct sockaddr_storage);
   ai->ai_addr = (struct sockaddr*)sa;
 
   *res = ai;
diff --git a/src/api/sockets.c b/src/api/sockets.c
index 429479ec..6026b84d 100644
--- a/src/api/sockets.c
+++ b/src/api/sockets.c
@@ -246,7 +246,9 @@ union sockaddr_aligned {
 #if LWIP_IPV6
    struct sockaddr_in6 sin6;
 #endif /* LWIP_IPV6 */
+#if LWIP_IPV4
    struct sockaddr_in sin;
+#endif /* LWIP_IPV4 */
 };
 
 #if LWIP_IGMP
diff --git a/src/include/lwip/sockets.h b/src/include/lwip/sockets.h
index 4db07f5a..a7b6ff41 100644
--- a/src/include/lwip/sockets.h
+++ b/src/include/lwip/sockets.h
@@ -59,6 +59,7 @@ typedef u8_t sa_family_t;
 typedef u16_t in_port_t;
 #endif
 
+#if LWIP_IPV4
 /* members are in network byte order */
 struct sockaddr_in {
   u8_t            sin_len;
@@ -68,6 +69,7 @@ struct sockaddr_in {
 #define SIN_ZERO_LEN 8
   char            sin_zero[SIN_ZERO_LEN];
 };
+#endif /* LWIP_IPV4 */
 
 #if LWIP_IPV6
 struct sockaddr_in6 {