diff --git a/sys/netinet/ip_carp.c b/sys/netinet/ip_carp.c
index 812caf31779..52e003b3fdc 100644
--- a/sys/netinet/ip_carp.c
+++ b/sys/netinet/ip_carp.c
@@ -76,6 +76,7 @@
 #include <netinet/icmp6.h>
 #include <netinet/ip6.h>
 #include <netinet6/ip6_var.h>
+#include <netinet6/scope6_var.h>
 #include <netinet6/nd6.h>
 #include <net/if_dl.h>
 #endif