diff --git a/dns/gethostbyaddr.c b/dns/gethostbyaddr.c
index b646948..6f6891a 100644
--- a/dns/gethostbyaddr.c
+++ b/dns/gethostbyaddr.c
@@ -2,6 +2,10 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
 #include "hstrerror.h"
 
 char *cmnd;