diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c
index 29be9a86..b6c1b86c 100644
--- a/sysdep/unix/io.c
+++ b/sysdep/unix/io.c
@@ -22,6 +22,7 @@
 #include <sys/un.h>
 #include <unistd.h>
 #include <errno.h>
+#include <netinet/in.h>
 #include <netinet/icmp6.h>
 
 #include "nest/bird.h"