diff --git a/ndhc/arp.c b/ndhc/arp.c
index c3c3863..c2b2664 100644
--- a/ndhc/arp.c
+++ b/ndhc/arp.c
@@ -10,7 +10,6 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/if_ether.h>
-#include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <sys/time.h>