--- a/src/configure.in
+++ b/src/configure.in
@@ -26,6 +26,7 @@
 #include<net/ethernet.h>
 #include<linux/if.h>
 #include<linux/in.h>
+#include <linux/in6.h>
 ])
 
 dnl Checks for typedefs, structures, and compiler characteristics.