diff --git a/sock.c b/sock.c
index 13e5bfb..9dc4661 100644
--- a/sock.c
+++ b/sock.c
@@ -1,6 +1,7 @@
 /* See LICENSE file for copyright and license details. */
 #include <arpa/inet.h>
 #include <netdb.h>
+#include <netinet/in.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <string.h>